Course Profile Mathematics of Data Management (MDM4U), Grade 12, University Preparation, Combined
Unit 5: Managing the Culminating Project
Activity 5.1 | Activity
5.2 | Activity 5.3 | Activity 5.4 | Activity
5.5 | Activity 5.6
Unit Description
Students prepare to
successfully complete the culminating project outlined in the Integration of
the Techniques of Data Management strand. Students engage in several activities
in which they apply several of the techniques/tools of the course to answer
significant questions. Each activity could be viewed as a mini-project,
providing the teacher with a vehicle for giving each student an opportunity to
prepare a written report, make a presentation to the class, and have it critiqued
by other students. The student gains valuable experience with these three
expectations that form part of their culminating project.
Time: 8 hours [in addition to the hours allocated
within Activities 5.2 to 5.6]
This
activity is a series of small activities, mini presentations, checklists, and
timing supports designed to guide students through a process to complete the
culminating project. The time allocated is spread throughout the course.
There are several opportunities for students to make presentations and receive
feedback. However it is expected that different students have opportunities in
each case. Students benefit from discussion and feedback after the
presentations as they apply the ideas to their own project development. The
planning and implementation process has been broken down into five stages that
align with the units of the course.
Stage 1: (1
hour) During Unit 1, students select a topic and establish a list of
significant questions to investigate for the culminating project. At the end of
the unit they should submit their proposals.
Stage 2: (3
hours) During Unit 2, students collect more data and begin analysis using
statistical tools. Students may work through guided Activities 5.2 and 5.3.
Presentations and reports may be prepared by individuals or groups; discussion
and feedback provide guidance.
Stage 3: (2
hours) Time allocated to apply the learning from Unit 3 to work with
culminating projects. Students work through guided Activity 5.3 and write
reports; selected students present their work. Feedback and discussion assist
students in making progress with their culminating projects.
Stage 4: (1
hour) During Unit 4, students work with additional tools if needed. Students
should be reaching the final stages of their projects.
Stage 5: (1 hour)
Time is allocated for students to finish their reports.
Ontario Catholic
School Graduate Expectations
CGE1i - integrates
faith with life.
Overall Expectations
DMV.01 - carry out a
culminating project on a topic or issue of significance that requires the
integration and application of the expectations of the course.
Specific
Expectations
DM1.01 - pose a
significant problem whose solution would require the organization and analysis
of a large amount of data;
DM1.02 - select and
apply the tools of the course to design and carry out a study of the problem;
DM 1.03 - compile a
clear, well-organized, and fully justified report of the investigation and its
findings.
·
Stages of the
planning process should be examined at the completion of each unit of the
course.
·
When planning
timelines for the course, it is important to build in the time allotted for
these management activities. Some of these activities are done with the class;
individual or group conferencing may be necessary to keep students on track.
Teachers may conference with each student on a regular basis, so that the
process remains ongoing. To allow time to for conferences, set aside class time
for students to work on their projects at midpoint and end of each unit. During
those classes, schedule short conferences with students to review the status of
their projects. A tracking sheet for students and teachers (see Appendix 5.1.1)
might serve as the initial page in a portfolio.
·
Depending on the
size of the class, individual projects and presentations may not be feasible.
As early in the course as possible, teachers need to decide if students may
work on a culminating project individually, in pairs, or in small groups. Some
topics may be larger issues than anticipated and it may be appropriate for two
or more students to examine several questions arising from the same topic. If
students are working on a culminating project together, it is important to
establish clear expectations. Each student involved is expected to apply the
skills and tools of the course to his/her part of the project, prepare a report
of the part, and present the part to the class. Students may work on different
aspects of the same issue, using the same or different sets of data, but doing
their individual analyses.
·
A student
portfolio would facilitate student/teacher conferences at the various stages.
Students include data and the sources of the data in their portfolios, helping
teachers to assess whether the proposal is feasible and helping students focus
or redefine their questions where necessary.
Stage 1: Posing a
significant problem that is the basis for the culminating project
Students choose an area of interest. Brainstorming project ideas in class may help students make a choice. Teachers stress that students need to choose a topic of personal interest. Ideally, they will be investing a lot of time and effort into this culminating project and it is important that they “own” the idea.
Students do a preliminary search for data before finalizing their choice of topic and posing the questions that they intend to answer. Teachers should consult the teacher-librarian about helping students perform a proper web search. Students may have trouble locating suitable data; they may need to redefine their questions or choose a different area of study. In other cases, new questions or areas of interest may surface from the preliminary search for data. A data search may reveal that the question posed is too big an issue or there are too many factors involved. It may be necessary to narrow or refine the question at various stages in the course.
The teacher plays the role of facilitator throughout this process and provides feedback. Other teachers and guest speakers could be used to open students’ eyes to how research affects our lives on and off the job.
Once students are
satisfied that there is sufficient data, they submit a proposal for the project
in writing. Teachers provide a deadline for proposals. The proposal should
include a hypothesis based on the student’s data search. Some class time should
be spent developing hypothesis statements. A sample proposal sheet is included
as (see Appendix 5.1.1). A rubric could be used to assess the proposal.
(See Appendix A.)
Stage 2: Applying
data analysis in the culminating project
After the completion
of Unit 2: Data Analysis, students revisit their culminating projects and apply
the acquired skills and concepts where appropriate. Since the culminating
project must involve the organization and analysis of a large amount of data,
the skills of this unit must be part of all culminating projects.
A checklist
of questions may help students with this process:
·
Is the data you
have collected pertinent to your project?
·
How valid is the
data?
·
What sampling
techniques were used to collect the data?
·
Is there possible
sampling bias and/or variability?
·
Have you
organized the data in a way that facilitates its manipulation and retrieval?
·
Have you computed
the measures of one-variable statistics (mean, median, mode, range,
interquartile range, variance, standard deviation) where appropriate?
·
Have you included
z-scores and percentiles where appropriate?
·
Have you chosen a
regression that models the relation between two variables?
·
Have you
described the relation between two variables by interpreting the correlation
coefficient?
·
Can the normal
distribution be applied with the data in your project?
After the study of one-variable statistics, it may be appropriate to
introduce Activity 5.2: Income in Canadian Families to give students an
opportunity to work through a guided example in how one-variable statistics
might be used. It would also be an opportunity for some students to practise
writing a report and making a presentation. At the end of Unit 2, students
could work on Activity 5.3: AIDS in Canada as an example of two-variable
statistics and an introduction to the concept of a simulation. Select group of
students could be asked to make a presentation.
Stage 3: Applying
counting and probability in the culminating project
Probability concepts
and simulating and predicting will not necessarily apply to all culminating
projects. After the completion of Unit 3: Counting and Probability, students
should revisit their culminating projects and apply the acquired skills and
concepts. A checklist of questions may help students with this process:
·
Can permutations
and combinations be applied in your project?
·
Is it possible to
consider probability problems associated with the data in your project?
·
Can empirical
probabilities be calculated and would this be appropriate in the context of
your project?
·
Is it possible
and appropriate to determine expected values in the context of your project?
·
Is it appropriate
to construct and use a probability distribution with your data?
·
Is it possible to
design a simulation as part of your culminating project?
·
If a simulation
is possible, have you assessed the validity of the simulation results?
At the end of Unit 3 students could work on Activity 5.4: Dice Games.
(Parts of Activity 5.4 could also be used as an introduction to probability
concepts, wrapping the activity up at the end of the unit.) A selected group of
students could make presentations.
Stage 4: Applying
additional tools for data management in the culminating project
After the completion
of Unit 4: Additional Tools for Data Management, students should revisit their
culminating projects:
·
Have you included
diagrams where appropriate?
·
Does graph theory
apply to your culminating project?
·
Can matrix tools
be applied to your culminating project?
Students should now be working towards finishing their final project.
Stage 5: Preparing
the report
Students should be aware of the expected components of their report. A
possible list might be:
·
Cover page
including a title that makes the purpose of their project apparent;
·
A clear statement
of the question to be considered;
·
Description of
procedure;
·
Presentation of
data using tables, charts, graphs;
·
Summary
statistics;
·
Evidence of the
use of technology;
·
Analysis of data
including calculations;
·
Conclusions;
·
Evaluation of
your techniques;
·
Bibliography.
Students should be aware that their report is to be assessed for its
mathematical validity. The mathematical content of their report should be
substantial. This project is their opportunity to demonstrate their
understanding of the skills and concepts of this course in an integrated
approach. Develop a rubric with students (see Appendix B) for assessing the mathematical
content of their reports.
It is important that
assessment strategies address the process as well as the final product for the
culminating project. Conferencing with students and assessing the various stages
in the planning process are useful for formative assessment. Assessment tools,
such as checklists, portfolios, and rubrics, are useful.
·
Students with
weak time-management skills may need closer monitoring. A calendar with clearly
indicated deadlines or meeting dates or contracts may be useful for setting due
dates for the various stages of the culminating project process. Students
should be encouraged to determine their own window for due dates.
·
Teachers should
refer to Individual Education Plans (IEPs) in place for their students in need
of accommodations (e.g., some students may need increased time to complete
tasks, while others may need more frequent conferencing to help them through
the process).
Student:
Presentation Date:
|
Stage |
Proposed Date of Completion |
Completion |
Conference Notes |
|
1. Proposal |
|
|
|
|
2. Data Collected |
|
|
|
|
3. Data Analysis One-Variable Two-Variable |
|
|
|
|
4. Other Tools |
|
|
|
|
5. Conclusions |
|
|
|
|
6. Written
Report |
|
|
|
|
7. Presentation Outline Technology Timing Checked |
|
|
|
|
Presentation Date: |
|||
Due Date:
Name:
(If you are working
in a group, include the names of other members of your group who are addressing
the same topic.)
The area of study I
intend to investigate is:
Why did you choose
this particular topic?
Do you have an
expectation about the results you will find?
I have done a
preliminary search for data and feel that the data is appropriate and
sufficient for the analysis that will be necessary. Based on this preliminary
data, the question I will consider is:
Time: 4 hours [use suggested at or near
the end of Unit 2]
In this open-ended
activity, with opportunity for further exploration, students analyse data about
family income in Canada over a 20-year period; they then use their analyses to
pose and answer questions. Students organize data from the Internet, creating suitable
intervals and a frequency table over several years, graph the frequency
distributions, and discuss changes and trends. Comparisons of the mean, median,
standard deviation, and quartiles are used to describe trends in the data
[before and after adjusting the income figures using the Consumer Price Index
(CPI) which they download from the Internet]. Z-scores and percentiles are used
to describe individual pieces of data.
Ontario Catholic
School Graduate Expectations
CGE3c - a reflective
and creative thinker who thinks reflectively and creatively to evaluate
situations and solve problems.
Overall
Expectations
ODV.01 - organize
data to facilitate manipulation and retrieval;
STV.01 - demonstrate
an understanding of standard techniques for collecting data;
STV.02 - analyse
data involving one variable, using a variety of techniques;
STV.05 - evaluate
the validity of statistics drawn from a variety of sources.
Specific
Expectations
OD1.01 - locate data
to answer questions of significance or personal interest, by searching
well-organized databases;
OD1.03 - create
database or spreadsheet templates that facilitate the manipulation and
retrieval of data from large bodies of information that have a variety of
characteristics;
ST1.04 - organize
and summarize data from secondary sources using technology;
ST2.01 - compute,
using technology, measures of one-variable statistics and demonstrate an
understanding of the appropriate use of each measure;
ST2.02 - interpret
one-variable statistics to describe characteristics of a data set;
ST2.03 - describe
the position of individual observations within a data set, using z-scores and
percentiles;
ST5.03 - explain the
meaning and the use in the media of indices based on surveys.
·
Use of a graphing
calculator to organize data in lists, compute measures of one-variable
statistics, and construct a histogram.
·
Students require
a graphing calculator or access to a spreadsheet or statistical software (e.g.,
Fathom) and Internet access. Students
can download the data for income by family from E-Stat. From the section
entitled People on the Table of
Contents, they select Personal Finance
and Household Finance (click on Data
at the bottom of the page, then Income
under Cansim II). It is suggested
that the income from Table 202-0401 be used because the income intervals go up
to $150 000. The individual income (Table 202-0101) data only goes up to income
of $60 000, but may be interesting data for further study of this issue. The
CPI data can also be downloaded from E-Stat, under Economy, Prices and Price Indexes. From the list of indexes, choose
Consumer Price Index. (Table
326-0002).
·
Students work
individually or in pairs. The pairing could be done randomly or by ability. It
may be appropriate to pair students of similar ability levels, but it may also
be effective to pair strong and weak students.
The purpose of this
activity is to introduce students to a significant problem: “Is the gap between
the rich and poor in Canada widening?” Students should discuss data or
information that would be useful in answering this question. This could be a
sensitive topic for some students. A search of Internet sites using the key
words “gap, rich, poor” will result in numerous articles and data which can be
used as an introduction as well as provide opportunities for further study. One
article, which examines the gap in Canada and the US, can be found at
www.statcan.ca/Daily/English/000728/d000728a.html
Ways to measure the
gap between rich and poor may include: the number of millionaires, number of
people who live below the poverty line, range of income, measures of spread,
etc. An article from the University of Toronto Varsity News, July 24, 2001 entitled “Youth hit hard as gap between
rich and poor grows, says report” may facilitate discussion
(www.varsity.utoronto.ca/archives/119/oct26/news/youth.html).
If Internet access
is limited, the data could be provided to students. (See Appendix 5.2.1.)
Students need to discuss ways to analyse and describe characteristics of the
data. Due to the volume of the data, suggestions can be made to look at
specific years at regular intervals (e.g., when considering data from 1980 to
1998, it may be useful to consider data from regular time periods – for
example: 1980, 1986, 1992, and 1998) To reduce the number of intervals, a
suggestion may be to use $25 000 intervals. The midpoints of the intervals are
used when calculating the measures of central tendency.
Questions
to consider:
·
What effect might
reducing the number of intervals have on the results?
·
What are the
implications of using $12 500 as the midpoint of the first income interval?
·
Is it reasonable
to use $162 500 as the midpoint of the over $150 000 interval?
The data is entered into a graphing calculator or computer software. The
midpoints of the intervals are placed in L1 and the percentage of
earners in each income interval placed in L2 through L5
for each of the four years considered. The mean, median, standard deviation,
and quartiles can be calculated for each year using the one variable statistics
on L1 and each of the four other lists. Compare these measures for
each of the four years.
Questions
to consider:
·
Are your
calculations the same as those provided by Statistics Canada? What might
account for the differences?
·
Are there any
patterns emerging?
·
How have each of
the measures changed from year to year?
·
What do the
changes in each measure tell us about the data?
·
What is the
percentage change in each of the measures from year to year?
·
Which measures
show the greatest percentage change for which years?
·
What does the
change tell us about the income levels of Canadians over these years?
·
When the z-score
is calculated for a family with an income of $30 000, how has the z-score
changed over the years?
·
If you repeat the
calculations for an income of $100 000, what conclusions can be made?
Frequency distributions for individual years can be drawn using the
graphing calculator. Different distributions can be drawn by hand and placed on
one graph using four different colours so that the distributions can be
compared.
·
What similarities
and differences do you notice in the distributions?
·
Are any patterns
apparent?
·
What do these
patterns tell us about the family income trends in Canada from 1980 to 1998?
Calculate the changes in percentages at each income level from 1980-1998
and construct a line graph of these changes. Examine the changes in the
frequencies for each income level.
·
What changes are
evident?
·
What does this
tell us about the trends in income?
·
Does this help us
answer the big question?
Use the Consumer Price Index to adjust the figures in terms of 1998
dollars. This can be done by multiplying the income interval midpoints by a
factor of 108.6/108.6 = 1 for 1998, 100/108.6 = .9208 for 1992, 78.1/108.6 =
0.7192 for 1986 and 52.4/108.6 = 0.4825 for 1980.
Recalculate the
mean, median, standard deviation, and quartiles for these inflation-adjusted
figures. Organize the results in a new table.
Questions
to explore:
·
Do these adjusted
figures change any of your previous conclusions?
·
What factors may
have caused family income in Canada to fall well behind inflation rates?
·
How has the
Canadian family changed from 1980 to 1998 (e.g., income earners, double-income
families, adult children contributing to family income, divorces, single-parent
families, part-time employment, etc.)?
Some students could be encouraged to pursue this issue further in a
culminating project.
·
The purpose of
this activity is to provide students with the opportunity to use skills that
will be necessary in their culminating project. Each student should have an
opportunity during the course to prepare a written report, make a presentation,
and critique the work of other students before they apply these skills to the
culminating project.
·
At this time it
would be reasonable for some students (or some pairs of students) to submit a
written report. Preparation of the report would require the use of graphing
software to print graphs of their data. Exposure to the technology is important
so that students feel comfortable using the software in their culminating
projects. The written report should be assessed for mathematical content. (See
sample rubric in Appendix B.)
Students’ IEPs may
suggest ways to support student learning that would be appropriate for this
activity. Extending an activity into a culminating project is a way for
students with special learning needs to get a “jumpstart” on their projects.
http://estat.statcan.ca
Income tables 202-0401,202-0101, CPI table 326-0002
www.ontario.cmha.ca
Canadian Mental Health Association, Backgrounder on Poverty, November 2000 This
report from the Ontario Child Health Study: Children at Risk examines the
correlation between being poor and having a much greater risk of suffering from
mental health problems.
www.statcan.ca/Daily/English/00728/d00728a.htm
- Article examines income inequality (gap between the rich and poor) in Canada
and U.S.
www.varsity.utoronto.ca/archives/119/oct26/news/youth.html
- Report states “Youth hit hard as gap between rich and poor grows.”
|
Group |
L1980 |
L1981 |
L1982 |
L1983 |
L1984 |
L1985 |
L1986 |
|
“Avg inc” |
47703 |
47479 |
46563 |
45451 |
45608 |
46526 |
47106 |
|
“Med inc” |
42250 |
41716 |
40416 |
38895 |
39216 |
39613 |
40062 |
|
0-5000 |
2.8 |
2.2 |
2.3 |
2.6 |
2.5 |
2.3 |
2.2 |
|
5000-9999 |
5.5 |
5.3 |
5.1 |
5.9 |
5.3 |
4.9 |
4.5 |
|
10000-14999 |
8 |
8.3 |
8.5 |
9.3 |
9.2 |
9.1 |
9.2 |
|
15000-19999 |
6.9 |
6.6 |
6.8 |
7 |
7.3 |
7.3 |
7.6 |
|
20000-24999 |
6.2 |
6.5 |
7.2 |
7.6 |
7.7 |
7.6 |
7.4 |
|
25000-29999 |
5.7 |
6.3 |
6.8 |
6.5 |
6.6 |
6.7 |
6.7 |
|
30000-34999 |
6 |
6.3 |
6.2 |
6.3 |
6.3 |
6.4 |
6.5 |
|
35000-39999 |
6 |
6.4 |
6.5 |
6.4 |
6.1 |
6.2 |
5.9 |
|
40000-44999 |
6.1 |
6.1 |
6.3 |
6.2 |
5.9 |
5.9 |
6.1 |
|
45000-49999 |
5.7 |
5.8 |
6 |
5.7 |
5.9 |
5.8 |
5.6 |
|
50000-54999 |
6.1 |
5.8 |
5.4 |
4.8 |
5.7 |
5.3 |
5.2 |
|
55000-59999 |
5.4 |
5.2 |
5.1 |
5.2 |
4.9 |
5 |
5 |
|
60000-64999 |
4.6 |
4.5 |
4.4 |
4.2 |
4.3 |
4.2 |
4.1 |
|
65000-69999 |
4.2 |
4.5 |
3.9 |
3.5 |
3.7 |
3.8 |
3.9 |
|
70000-74999 |
3.7 |
3.5 |
3.3 |
3.1 |
3.2 |
3.4 |
3.4 |
|
75000-79999 |
3.1 |
2.6 |
2.8 |
2.7 |
2.7 |
2.7 |
2.8 |
|
80000-84999 |
2.6 |
2.5 |
2.2 |
2.3 |
2.1 |
2.3 |
2.4 |
|
85000-89999 |
2 |
2.2 |
1.9 |
1.9 |
1.8 |
2 |
2 |
|
90000-99999 |
2.8 |
3 |
2.9 |
2.8 |
2.7 |
2.8 |
2.9 |
|
100000-124999 |
3.8 |
3.9 |
3.6 |
3.3 |
3.5 |
3.8 |
3.8 |
|
125000-149999 |
1.5 |
1.5 |
1.5 |
1.6 |
1.3 |
1.5 |
1.5 |
|
150000 and over |
1.4 |
1.1 |
1.2 |
1.2 |
1.3 |
1.2 |
1.5 |
|
L1987 |
L1988 |
L1989 |
L1990 |
L1991 |
L1992 |
L1993 |
L1994 |
L1995 |
L1996 |
L1997 |
L1998 |
|
47420 |
48429 |
49913 |
49116 |
47487 |
47603 |
46416 |
47254 |
47246 |
47476 |
48124 |
49797 |
|
39975 |
4730 |
42455 |
41294 |
39137 |
39766 |
38061 |
39255 |
38608 |
38613 |
38325 |
39398 |
|
2 |
1.8 |
1.5 |
1.7 |
2 |
2 |
2.1 |
1.7 |
1.9 |
2.4 |
2.4 |
2.3 |
|
5 |
4.8 |
4 |
4.2 |
4.9 |
4.7 |
4.7 |
5.2 |
4.8 |
5.2 |
5.2 |
5 |
|
9 |
8.9 |
8.5 |
8.8 |
8.9 |
8.9 |
9.4 |
8.8 |
8.9 |
9.4 |
9.3 |
9.1 |
|
7.1 |
7 |
7.2 |
7.2 |
7.6 |
7.7 |
8.1 |
8.6 |
8 |
7.8 |
7.8 |
7.3 |
|
7.7 |
7.3 |
7.3 |
7.6 |
7.5 |
7.4 |
8 |
7.4 |
8.1 |
7.4 |
7.4 |
7.3 |
|
6.9 |
6.8 |
6.2 |
6.6 |
6.9 |
7.1 |
6.8 |
6.5 |
6.7 |
7.1 |
7 |
7.2 |
|
6.2 |
6.4 |
6.3 |
6.2 |
6.9 |
6.7 |
7.1 |
6.4 |
6.9 |
6.4 |
6.7 |
6.7 |
|
6.3 |
6.1 |
6.3 |
6.1 |
6.5 |
5.8 |
6 |
6.3 |
6.3 |
5.9 |
6.2 |
5.8 |
|
5.8 |
5.6 |
5.9 |
5.6 |
5.6 |
6.1 |
5.9 |
5.9 |
6 |
5.8 |
5.2 |
5.5 |
|
5.8 |
5.7 |
5.9 |
5.7 |
5.5 |
5.3 |
5.1 |
5.1 |
5.2 |
4.8 |
4.9 |
4.9 |
|
5.3 |
5.2 |
5.3 |
5 |
4.6 |
5 |
4.7 |
5.2 |
4.8 |
4.9 |
4.8 |
4.7 |
|
4.7 |
4.5 |
4.9 |
4.8 |
4.8 |
4.6 |
4.3 |
4.6 |
4.4 |
4.6 |
4.2 |
4.5 |
|
4.1 |
4.2 |
4.4 |
4.4 |
3.9 |
4.1 |
4.4 |
4.3 |
3.9 |
4.2 |
4.2 |
3.6 |
|
3.8 |
4.1 |
3.7 |
3.8 |
3.6 |
3.7 |
3.2 |
3.6 |
3.6 |
3.7 |
3.6 |
3.7 |
|
3.3 |
3.2 |
3.2 |
3.3 |
3.5 |
3.2 |
3.1 |
3.1 |
3 |
3.1 |
3 |
3.3 |
|
2.6 |
2.9 |
3.1 |
2.8 |
2.7 |
2.8 |
2.6 |
2.5 |
2.7 |
2.7 |
2.6 |
2.8 |
|
2.3 |
2.4 |
2.5 |
2.6 |
2.2 |
2.2 |
2.3 |
2.2 |
2.3 |
2.4 |
2.3 |
2.1 |
|
2 |
2.1 |
2.1 |
2.1 |
1.9 |
2.1 |
2 |
1.9 |
2 |
1.9 |
1.8 |
2 |
|
3 |
3.2 |
3.3 |
3.4 |
3.1 |
3.3 |
3.1 |
3 |
2.9 |
2.7 |
3.3 |
3.2 |
|
4 |
4.4 |
4.7 |
4.5 |
4.1 |
4.3 |
3.9 |
4.3 |
4 |
4.4 |
4.1 |
4.9 |
|
1.6 |
1.6 |
1.9 |
1.7 |
1.7 |
1.6 |
1.5 |
1.9 |
1.6 |
1.7 |
1.9 |
2 |
|
1.6 |
1.8 |
1.8 |
1.9 |
1.6 |
1.6 |
1.4 |
1.5 |
1.7 |
1.7 |
2 |
2.3 |
|
Year |
CP1 |
|
1980 |
52.4 |
|
1981 |
58.9 |
|
1982 |
65.3 |
|
1983 |
69.1 |
|
1984 |
72.1 |
|
1985 |
75 |
|
1986 |
78.1 |
|
1987 |
81.5 |
|
1988 |
84.8 |
|
1989 |
89 |
|
1990 |
93.3 |
|
1991 |
98.5 |
|
1992 |
100 |
|
1993 |
101.8 |
|
1994 |
102 |
|
1995 |
104.2 |
|
1996 |
105.9 |
|
1997 |
107.6 |
|
1998 |
108.6 |
Time: 4 hours [use suggested at or near
the end of Unit 2]
Students analyse
data relating to the spread of AIDS in Canada over the last twenty years.
Measures of central tendency are used to describe the characteristics of the
data and their applicability as predictors. The trends in the data over time
are examined, and a linear model applied. The correlation coefficient and the
graph are used to consider the appropriateness of the linear model in making
predictions. A simulation is constructed and the results compared and
contrasted with the actual data. Adjustments are made to the simulation model
until the produced data closely reflects the actual data. Once refined, the
data from the simulation is used to make predictions about the future. The
reliability of this model is assessed.
Ontario Catholic
School Graduate Expectations
CGE1d - develops
attitudes and values founded on Catholic social teaching and acts to promote
social responsibility, human solidarity, and the common good;
CGE2a - listens
actively and critically to understand and learn in light of gospel values.
Overall
Expectations
ODV.01 - organize
data to facilitate manipulation and retrieval;
CPV.03 - design and
carry out simulations to estimate probabilities;
STV.01 - demonstrate
an understanding of standard techniques for collecting data;
STV.04 - describe
the relationship between two variables by interpreting the correlation
coefficient.
Specific
Expectations
OD1.02 - use the
Internet effectively as a source for databases;
CP3.01 - identify
the advantages of using simulations in contexts;
CP3.02 - design and
carry out simulations to estimate probabilities;
ST1.04 - organize
and summarize data from secondary sources using technology;
ST4.01 - define the
correlation coefficient as a measure of the fit of a scatter graph to a linear
model;
ST4.02 - calculate
the correlation coefficient for a set of data, using graphing calculators or
statistical software;
ST4.04 - describe
possible misuses of regression.
Use of a graphing
calculator to organize data in lists, compute measures of one-variable
statistics, construct a scatter plot, perform a linear regression, use formulas
in lists, and generate random numbers.
The data can be
provided or students can access the data at www.hc-sc.gc.ca. Students work in
pairs. Each pair requires a graphing calculator. Students should be given the
worksheet to facilitate the collection of the data during the simulation.
Access to software for printing graphs may be useful (e.g., TI-Graphlink, Fathom, TI-Interactive, Excel,
or Quattro Pro).
The teacher should
be sensitive to individual circumstances. The main questions are “What is the
predicted future growth of AIDS cases in Canada?” and “Can we use past data to
predict what might happen when there is an outbreak of a disease?”
In the early 1990s,
there was a fear that AIDS would become an epidemic and it would run rampant
throughout the population. Discussion of factors that might influence the
spread of AIDS could include age, attitude about risk, education, and
prevention.
The table
gives the number of reported AIDS cases by year of diagnosis:
|
Year |
1979 |
1980 |
1981 |
1982 |
1983 |
1984 |
1985 |
1986 |
1987 |
1988 |
1989 |
|
# of Cases |
1 |
5 |
9 |
26 |
66 |
164 |
375 |
632 |
953 |
1159 |
1387 |
|
1990 |
1991 |
1992 |
1993 |
1994 |
1995 |
1996 |
1997 |
1998 |
1999 |
2000 |
|
1433 |
1556 |
1732 |
1758 |
1733 |
1579 |
1063 |
688 |
599 |
415 |
261 |
After students
examine the data, discuss underlying reasons for the trends that are evident.
Students enter the
number of cases from 1979 to 1998, a span of twenty years, into a list on a
graphing calculator. Enter the years into L1 using 1979 as year 1
and the number of cases into L2. (Retain the data for subsequent
years as a test of the validity of the models developed.)
Method 1: Measures
of Central Tendency
Students calculate
the measures of central tendency using the graphing calculator and use them to
describe the characteristics of this set of data. The mean, median, or mode is
often useful to represent a set of data. Does the mean or median appear to be a
good predictor for this data? Why would the mode not be used? Compare the
prediction with the actual figures for the year 2000. What if only the last ten
years were used? Would you use the mean or median as a predictor? Justify.
Method 2: Line of
Best Fit
In order to
investigate the trend over time, students consider the cumulative number of
cases reported. The cumulative sum can be entered into L3 using the
cumSum command in the List OPS menu of the graphing calculator. Next, students
consider the relationship between two variables by looking at the trends in the
data over time. Create a scatter plot of the total cases reported versus the
year (1-20). Use a linear regression to determine the line of best fit and
consider the resulting correlation coefficient. Students should assess the
validity of the model on the basis of this coefficient and the graph. Does it
make sense that the number infected per year increases and then decreases? Use
the linear model to predict the number of reported cases of AIDS in the year 2000.
Compare the prediction to the actual number of reported cases. Is the
prediction accurate?
Further questions to
consider:
·
In theory, if we
extrapolate with the linear model, the whole population will be infected. Is
this realistic?
·
Are there any
outliers? What if we excluded the outliers?
·
What if we used
only the last ten years? Is this model a good fit?
·
What are some
limitations of the linear model?
Method 3:
Simulation
The simulation models the spread of an infectious disease in a population. Although the original design is laid out, there is opportunity for students to redesign the model.
Suppose there are 100 people in a population and one of these people is infected with a disease. Suppose each infected person infects one other person in the population each year. Using a graphing calculator, students use random numbers between 1 and 100 to model the spread of the infection. Construct a table containing numbers 1 to 100 to keep track of those infected over a 20-year period. At the start (year 0), one person is infected. Use the random number generator on a graphing calculator to select the infected person. Place an X in the chart to indicate infection. In year 1, another person becomes infected (chosen by a random number). In year 2, both infected people come into contact with other people (chosen by two random numbers) and those people become infected. Indicate these with X’s. The random integer function can be used to produce a specific number of random numbers (e.g., if there are 12 infected people in a particular year, during the following year, 12 more people could become infected). By using RandInt (1,100,12), 12 random numbers appear on the screen. You may need to scroll to see all the numbers.
In a second table, keep track of the cumulative number infected in the population for each year.
Remind students that, once infected, a person cannot be re-infected, so some of the contacts will not result in new infections. Continue until year 20 (or when the entire population is infected).
Students who are familiar with computer programming may design a computer program to run this simulation (see Turing and C++ examples in Appendix E). A TI-83 program [available at www.ugdsb.on.ca\cddhs\math] could be used.
Doing a simulation only once is not sufficient to conclude that this is the pattern. Why might this be the case? Often a simulation needs to be repeated a number of times to see if a pattern develops. Use a table to collect cumulative number of infections from other students’ simulations and average the results. Is there a pattern developing? On average, how many years did it take for the entire population to be infected?
Place the simulated number of cases (averaged from the simulations done by the class) in L4. Graph the simulated data L4 versus L1. Compare this graph to the graph of the AIDS data (L3 versus L1). How does the simulation compare as a model?
Students should notice that the general shape of the graph of the simulated data is similar to the actual data; there is a sharp increase in the number of cases initially and then a levelling off as time progresses. The simulation model is certainly better than the linear model - in general the simulation curve appears to be similar to the actual. It may increase or decrease too quickly and, of course, the entire population is infected in the simulation.
Is it possible to map the simulation data so that it is similar to the actual curve? Since Canada has a population of about 30 million and our population was 100, we could multiply the cases by 300 000. Does this appear realistic? Explain. The simulation was done with a population of 100, with all persons having the same likelihood of contracting the disease. Is this realistic? Explain. The rate of increase may be too quick or slow in our simulation. We assumed an infection every year. It may be less or more. Multiply your time values (L1) by an appropriate factor. Place this data in L5. (Try 0.5 or 2 to get a sense of how the graph might change.)
The number infected in our population in comparison is quite different. Multiplying by 300 000 is not realistic. Multiply the infected column (L4) by a factor. Place this data in L6. (Try 50 or 100 to get a sense of how the graph might change.)
Using the modified simulation model, what would you predict about future trends for AIDS cases in Canada? Is this an appropriate model? Justify.
Some further
questions to consider:
·
Why does this
levelling out in the graphs occur?
·
What are some of
the factors affecting the maximum number of people that are likely to become infected
over time?
·
What are some of
the limitations of this simulated model?
Research the incidence of AIDS in other countries. Do the same trends
appear?
Research the
incidence of other diseases within populations. Are the trends similar?
Once students have
completed the activity, the class could discuss: What information should be
included in a written report and how should it be displayed? What should be
included in a presentation? What further investigation is appropriate?
·
The purpose of
this activity is to provide students with the opportunity to use skills that
will be necessary in their culminating project. Some pairs of students may
submit a written report, which should be assessed for mathematical content.
(See rubric in Appendix B)
·
Some pairs may
make a presentation to the class. Teachers assess students on their
presentation skills as well as the mathematical content of their presentation.
(See rubric in Appendix C.) Refer to Activity 5.6 for more suggestions about
presentations and their assessment.
·
Students should
practise critiquing the presentations of other students for effectiveness.
Feedback from peers should not be part of the student’s assessment. Critiquing
is intended to provide feedback (positive as much as possible); feedback should
be viewed as formative assessment to help students improve their presentation
skills. The presentation rubric in Appendix C could be used by teachers and
students, or a simpler checklist, such as the sample in Appendix D, might be
easier for students with little experience with critiquing.) Refer to Activity
5.6.
Health Canada –
www.hc-sc.gc.ca (data on Aids cases)
Time: 3 hours
Dice games have been
popular since ancient times. The study of probability began because of interest
in games of dice. The famous French nobleman and professional gambler Chevalier
de Mere (1607-1684) corresponded with Blaise Pascal about his chances in a dice
game. De Mere wanted to know which had the higher probability: getting at least
one “6” in four rolls of a die (
) ) or getting at least one double-six in 24 throws of two
dice (
) ) . De Mere suspected that the first had a higher
probability than the second, but his mathematical skills were not great enough
to demonstrate why this should be so. De Mere’s observation remains true even
if two dice are thrown 25 times, since the probability of throwing at least one
double-six is then
.. This dice problem has since been known as de Mere’s
Problem. A National Film Board Video, Of
Dice and Men, goes through the history of De Mere and introduces
probability.
The challenge is
that the probability is not always what it seems in many games. Often the
appearance of fairness has been used to the advantage of others in gambling
situations. In this activity, students consider two dice games: one involves
dice differences and the other involves non-transitive dice. (The
non-transitivity paradox is where although A is preferred to B and B is
preferred to C, A is not preferred to
C.) Students examine the probability concepts that underlie both games.
Ontario Catholic
School Graduate Expectations
CGE5a - works
effectively as an interdependent team member;
CGE3b - creates,
adapts, and evaluates new ideas in light of the common good.
Overall
Expectations
CPV.02 - determine
and interpret theoretical probabilities, using combinatorial techniques;
CPV.03 - design and
carry out simulations to estimate probabilities.
Specific
Expectations
CP2.01 - solve
probability problems involving combinations of simple events, using counting
techniques;
CP2.02 - identify
examples of discrete random variables;
CP2.04 - calculate
expected values and interpret them within applications as averages over a large
number of trials;
CP2.05 - determine
probabilities using the binomial distribution;
CP2.06 - interpret
probability statements, including statements about odds, from a variety of
sources;
CP3.01 - identify
the advantages of using simulations in contexts;
CP3.02 - design and
carry out simulations to estimate probabilities;
CP3.03 - assess the
validity of some simulation results by comparing them with the theoretical
probabilities.
Students should
understand the basic concepts of probability. The experimental part of each
activity can be used as an introduction to the unit on probability. Students
can return to the activity and investigate the underlying theoretical
probabilities after they have studied the concepts in more detail.
Note: This activity uses data from the use of dice. Teachers should handle the activity in such a way to ensure that the gambling aspect is not glamorized or presented as a positive adventure.
Part A - Dice
Differences
Students play the
game in pairs. Each set of players needs a pair of dice or a TI-83 graphing
calculator with the DICEDIFF program.
Part B:
Non-Transitivity Paradox
Non-transitive dice
demonstrate a probability that challenges our intuition and traps the unwary.
You may want to introduce the topic by telling students about a meeting between
Warren Buffet, the investor and Bill Gates, the chairman of Microsoft. In an
article by Andrew Kupfer in Fortune
Magazine
dated 02-05-1996, Bill Gates describes his relationship with Buffet:
“One area in which we do joust now and then is mathematics. Once Warren presented me with four unusual dice, each with a unique combination of numbers (from 0 to 12) on its faces. He proposed that we each choose one of the dice, discard the third and fourth and wager who would roll the highest number most often. He graciously offered to let me choose first. Then he said, “Okay, because you get to pick first, what kind of odds will you give me?” I knew something was up. “Let me look at those dice”, I said. After studying the numbers on their faces for a moment, I said, “This is a losing proposition. You choose first.” Once he chose a die, it took me a couple of minutes to figure out which of the three remaining dice to choose in response. Because of the careful selection of the numbers on each die, they were non-transitive. Each of the four dice could be beaten by one of the others: die A would tend to beat die B, die B would tend to beat die C, die C would tend to beat die D, and die D would tend to beat die A. This meant that there was no winning first choice of a die, only a winning second choice. It was counterintuitive, like a lot of things in the business world.”
It may be most effective to construct a large set of non-transitive dice
to be used in the classroom setting. Challenge students to pick one die in a
game of The Best of Ten Throws. By choosing the appropriate die, odds are such
that you should win almost every time. There are several sets of non-transitive
dice. (They can be purchased online – www.grand-illusions.com/magicdice.htm)
One possible set is:
Dice A: 6,6,2,2,2,2 Dice
B: 5,5,5,1,1,1
Dice C: 4,4,4,4,0,0 Dice D: 3,3,3,3,3,3
(Other sets may have
an increased probability of winning, but with this set the probability between
each pair of dice is the same.)

www.grand-illusions.com/magicdice.htm
Other similar sets
are:
Dice A:
11,10,9,3,3,2 Dice
A: 11,10,9,3,2,1
Dice B: 8,8,8,7,1,0 Dice
B: 9,8,8,7,1,0
Dice C: 6,6,6,6,5,5 Dice
C: 7,7,6,6,5,5
Dice D:
12,12,4,4,4,4 Dice
D: 12,11,5,4,4,3
Some three dice
non-transitive sets are:
Dice A: 4,4,4,4,1,1 Dice
A: 7,7,5,5,3,3
Dice B: 3,3,3,3,3,3 Dice
B: 9,9,4,4,2,2
Dice C: 5,5,2,2,2,2 Dice
C: 8,8,6,6,1,1
Part A - Dice
Differences
One player is the
Low player and the other is the High player. The dice are rolled and the
difference is calculated. The differences will range from zero (if the upfaces
are the same) to 5 (if a 1 and a 6 are rolled). If the dice difference is 0, 1,
or 2, the Low player wins. If the dice difference is 3, 4, or 5, the High
player wins. Students play 25 rounds and record who wins each round and who
wins overall.
Note: Students can
get the necessary data quickly using a TI-83 program instead of rolling the
dice (see the TI-83 manual for more detailed instructions):
PROGRAM:DICEDIFF
:Lbl D
:rand Int(1,6) >
A
:rand Int(1,6) >
B
:Disp abs(A-B)
:Pause
:Goto D
Once the program is
executed, the student presses the Enter key seven times to get a new screen
with seven new pieces of data, recording them in a tally chart, seven at a
time.
Does the game appear
to be fair to both players?
Data from the whole
class can be compiled. Use the class results to determine the experimental
probability of each player winning. Compute the theoretical probability of each
difference outcome. (A grid of the possible outcomes could be suggested to
students as a strategy.) Construct a probability distribution for the possible
outcomes.
Compute the
theoretical probability of each player winning.
It turns out that
the game is not fair. How could the rules be changed to make it fair? Compute
the probabilities for the altered game to illustrate the fairness.
A variation of this
game is Prisoners. Each player requires a playing board of 6 cells, 6 counters
to represent the prisoners, and 2 dice (for each pair). Each player places
their prisoners into any cells on their own game board. Players may place one
prisoner in each cell, or two in some cells and none in others, or all six in
one cell. Take turns rolling the dice. Calculate the difference. The player
rolling the dice may release one prisoner from the cell with that number. The
winner is the first to release all their prisoners.

Keep a record of
where you place your prisoners for each game, then record the ones that were
winners. What combination appears to be a winning strategy? Compare your
results with the rest of the class.
|
|
Cell |
Winners |
|||||
|
|
0 |
1 |
2 |
3 |
4 |
5 |
|
|
|
2 |
2 |
1 |
1 |
0 |
0 |
X |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Test two of the best
combinations from the class against each other. Record the number of tosses it
takes to release all the prisoners for each combination, as well as recording
the winner. (If one combination wins after 8 tosses, keep tossing until all
prisoners are released for the losing combination as well.) Repeat the game
several times. Compile the results for the class.
Tally the
experimental results in a table for each of the combinations (e.g., if Combination
2 won the game in 9 tosses and Combination 1 took 11 tosses to release all
prisoners, tally the results):
|
Number of Rolls Necessary |
Combination 1 |
Comb. 1 Wins |
Combination 2 |
Comb. 2 Wins |
|
6 |
|
|
|
|
|
7 |
|
|
|
|
|
8 |
|
|
|
|
|
9 |
|
|
X |
X |
|
10 |
|
|
|
|
|
11 |
X |
|
|
|
|
12 |
|
|
|
|
|
13 |
|
|
|
|
|
14 |
|
|
|
|
|
15 |
|
|
|
|
|
More than 15 |
|
|
|
|
|
Totals |
|
|
|
|
Compute the
experimental probability that all prisoners will be released in 6 tosses, 7
tosses, etc. for each of the combinations. What is the experimental probability
that one combination will win over the other combination? Compute the
theoretical probability that all prisoners will be released in 6 tosses, 7
tosses, etc., for each of the combinations. Do the experimental probabilities
approximate these theoretical probabilities? Which combination should be the
most successful in theory? Do the experimental results support this theory?
Part B:
Non-Transitivity Paradox
As the class
challenge is carried out, students record the winner of each roll as well as
the winner in The Best of 10 Throws. What is the experimental probability that
the teacher will win on a single roll? What is the theoretical probability that
die A beats B? Students being introduced to probability may use a grid:
The Winning Player
|
A / B |
5 |
5 |
5 |
1 |
1 |
1 |
|
6 |
A |
A |
A |
A |
A |
A |
|
6 |
A |
A |
A |
A |
A |
A |
|
2 |
B |
B |
B |
A |
A |
A |
|
2 |
B |
B |
B |
A |
A |
A |
|
2 |
B |
B |
B |
A |
A |
A |
|
2 |
B |
B |
B |
A |
A |
A |
Similarly, calculate
the probability that B beats C, C beats D, and D beats A. What is the
probability that the teacher wins in exactly 5 games? What is the probability
that the teacher wins in exactly 6 games?
7 games? 8 games? 9 games? 10 games?
Individual
Calculations for Winning in 5 Games and 10 Games
(http://exploringdata.cqu.edu.au)
|
5 Games |
|||||
|
Teacher |
|
|
Student |
|
|
|
No. games |
5 |
|
No. games |
5 |
|
|
P(wins game) |
0.667 |
|
P(wins game) |
0.333 |
|
|
Probability
teacher wins in: |
Probability
student wins in: |
||||
|
5 |
0.132 |
|
5 |
0.004 |
|
|
6 |
0.219 |
|
6 |
0.014 |
|
|
7 |
0.219 |
|
7 |
0.027 |
|
|
8 |
0.171 |
|
8 |
0.043 |
|
|
9 |
0.114 |
|
9 |
0.057 |
|
|
Total |
0.855 |
|
Total |
0.145 |
|
|
10
Games |
|||||
|
Teacher |
|
|
Student |
|
|
|
No. games |
10 |
|
No. games |
10 |
|
|
P(wins game) |
0.667 |
|
P(wins game) |
0.333 |
|
|
Probability
teacher wins in: |
Probability
student wins in: |
||||
|
10 |
0.017 |
|
10 |
0.0000 |
|
|
11 |
0.058 |
|
11 |
0.0001 |
|
|
12 |
0.106 |
|
12 |
0.0004 |
|
|
13 |
0.141 |
|
13 |
0.0011 |
|
|
14 |
0.153 |
|
14 |
0.0024 |
|
|
15 |
0.143 |
|
15 |
0.0045 |
|
|
16 |
0.119 |
|
16 |
0.0074 |
|
|
17 |
0.091 |
|
17 |
0.0113 |
|
|
18 |
0.064 |
|
18 |
0.0161 |
|
|
19 |
0.043 |
|
19 |
0.0214 |
|
|
Total |
0.935 |
|
Total |
0.0648 |
|
Design a simulation to model the results with
this set of dice. How do the simulated results compare with the theoretical
probabilities? Investigate other sets of non-transitive dice. Try creating your
own set. Compute the resulting probabilities. Test your set and compare the
experimental results with the theoretical probabilities of winning. Design a
simulation to model the results of this set of dice.
Have a class
discussion about how these probability concepts might apply to the culminating
projects.
Part A - Dice
Differences
·
Students could
present the dice differences game with the altered rules to the class. If time
allows, the class could play the altered game and determine if the results
illustrated the theoretical probabilities that students had determined. The
open-ended nature of designing their own rules may lead students towards
further investigation in game theory.
·
Prisoners can be
used as a class activity. The emphasis on experimental results is handled more
easily by compiling class results. It can be used to introduce the concept of
probability distributions, or as an assessment after students have learned the
concepts. For assessment, students might work in pairs and present their
findings, both experimental and theoretical, in the form of a written report.
Part B:
Non-Transitivity Paradox
·
This activity can
be used as an introduction to the probability unit. Experimental results can be
collected. Then, after the probability concepts have been fully developed,
students can return to the unit and complete the theoretical computations and
design the simulations.
·
If used as a
summary activity for the unit on probability, students could work in pairs to
collect the experimental data. A written report comparing the experimental
results with the theoretical computations could be part of the assessment.
·
If students
construct their own set of non-transitive dice or design a simulation of a set
of dice, a class presentation may be appropriate.
Students with
similar skill levels should be paired. This allows more time for the teacher to
assist students experiencing difficulty. See the overview for further
suggestions for accommodations.
http://exploringdata.cqu.edu.au/
A resource for data and other probability activities.
National
Film Board. Of Dice and Men. A video
about De Mere and probability concepts.
www.grand-illusions.com/magicdice.htm
A website offering non-transitive dice (magic dice)
Time: 1 hour
The tools from Unit
4 may provide students with an alternative way to organize and present their
data. This activity considers tools that may be useful in some culminating
projects and suggest possible avenues for students to consider.
One suggestion for a
culminating project may be a study of fractals. Fractals are self-replicating
shapes (i.e., as you focus on a portion of the shape it maintains the same
geometrical shape). This part of the activity looks at one of the most famous
fractals, Sierpinski's Triangle.
Another focus for a
culminating project may be on problems involving networking, graph theory, and
matrices. A networking problem may be illustrated in the form of a graph using
vertices and edges or a matrix where each row and column represents a vertex in
the network. This part of the activity looks at another famous problem - the
Koenigsberg bridge problem.
Ontario Catholic
School Graduate Expectations
CGE2b - reads,
understands, and uses written materials effectively;
CGE3b - creates,
adapts, and evaluates new ideas in light of the common good.
Overall
Expectations
ODV.02 - solve problems involving complex relationships, with the aid of
diagrams;
ODV.03 - model
situations and solve problems involving large amounts of information using
matrices.
Specific
Expectations
OD2.01 - represent
simple iterative processes using diagrams that involve branches and loops;
OD2.02 - represent
complex tasks or issues using diagrams;
OD2.03 - solve
network problems using introductory graph theory;
OD3.01 - represent
numerical data, using matrices and demonstrate an understanding of terminology
and notation related to matrices;
OD3.02 - demonstrate
proficiency in matrix operations, including addition, scalar multiplication,
matrix multiplication, the calculation of row sums and the calculation of
column sums, as necessary to solve problems, with and without the aid of
technology;
OD3.03 - solve
problems drawn from a variety of applications using matrix methods.
These activities may
be used to introduce the concepts of iterative processes and graph theory or as
samples at the end of the unit to prompt further exploration.
Each part of the
activity is independent. Students may look at just one of the components of
iteration, networking, or matrices.
Part A: The
Sierpinski Triangle:
One of the most
famous fractals is Sierpinski's Triangle.
An algorithm for it
is as follows:
1. Draw a triangle.
2. Construct a point at the midpoint of each
side and form another triangle using the three midpoints as vertices. Four
triangles result: one in the middle, and three surrounding it.
3. Shade in the newly formed middle triangle.
4. Repeat steps 2 and 3 for the three white
triangles surrounding the newly created one as often as possible.
Perform the above algorithm to draw Sierpinski’s Triangle.
Geometer’s Sketchpad contains a pre-made script that creates Sierpinski’s
triangle. The file, sirpnski.gss, can be located under
\samples\scripts\fractals\sirpnski.
It is possible to
generate the triangle by introducing randomness. Although points are drawn
based on the selection of a random number, the same image results after many
iterations. It is possible to construct by hand but many iterations are
required. Results are better if a computer program is used that can quickly
perform the iterations. The Guide Book
for the TI-83 Plus calculator has a sample program on pp. 17-7.
The algorithm is as
follows:
1. Set up a grid of a reasonable size, a
suggestion may be 12 by 12.
2. Randomly select starting coordinates x and y.
3. Roll a die.
4. If 1 or 2 is rolled, recalculate x and y on the basis of the following: x = 0.5x, y = 0.5y
5. If 3 or 4 is rolled, recalculate x and y on the basis of the following: x = 0.5(0.5+x), y = 0.5(1+y)
6. If 5 or 6 is rolled, recalculate x and y on the basis of the following: x = 0.5(1+x), y = 0.5y
7. Plot the new point.
8. Repeat steps 3 to 7.
Perform the
algorithm a number of times to draw Sierpinski's Triangle.
Extensions:
Research other fractals
and describe the steps in an algorithm or in a flow chart (e.g., Koch’s
Snowflake, Julia Sets, Barnsley’s Fern, Mandelbrot set, etc.). If you are proficient
in computer programming or programming on the calculator you may create your
own program. Michael Barnsley, author of Fractals
Everywhere, suggests it is possible to determine a fractal algorithm for a
given image and send the algorithm over the Internet rather than the actual
image, thus reducing the time taken for transferring information.
Part B: The Seven
Bridges of Konigsberg
Konigsberg was a
city in Prussia situated on the Pregel River. The city is called Kaliningrad
today and is a major industrial centre in western Russia. The river Pregel
flowed through the town creating an island. Seven bridges spanned the various
branches of the river. Some of the town’s curious citizens wondered if it was
possible to travel across all seven bridges without having to cross any bridge
more than once. All who tried, failed.
The problem can also
be described as drawing the picture without retracing any line and without
lifting the pencil from the paper. If the path is traceable, it is called an
Euler path. Students might investigate various diagrams, identifying Euler
paths or create challenge diagrams for classmates to try.

www.contracosta.cc.ca.us/math/Konig www.jcu.edu/math/vignette/bridges.htm
Network problems
such as this can be solved using graph theory. Name each of the land areas as
the vertices and the bridges joining these areas as the edges. The order of a
vertex is the number of edges at that vertex. If we consider one of the
vertices with order 3: If we start at this vertex, we leave by one bridge, and
return by another. This means that we must leave again to cross the third
bridge. If we start elsewhere, we would pass through this vertex by entering on
one bridge, leaving by another. We would have to return to cross the third
bridge, therefore ending at that vertex. This means our trip must either begin
or end on this vertex since it has three edges, making it an odd vertex. The
same argument would hold for the other vertices, which are also odd. Since we
cannot begin or end at more than two vertices, the trip is impossible. (To be
possible, there would have to be just two odd vertices. We would begin at one
and end at the other.)
Such problems can be
put in a context. (Suppose you are given the map of a town and told to design a
route for snowplows. Is it possible to plough every street without ploughing
any street more than once?) Students are encouraged to create a context (e.g.,
see www.jcu.edu/math/vignettes/bridges,
www.bridges.canterbury.ac.nz/features/bridges, www.sunybroome.edu/~mat_dept/current/113konig,
www.contracosta.cc.ca.us/math/Konig).
Network problems can
be modelled using matrices. Each row or column would represent the vertex and
the entries of the matrix represent the number of direct edges joining the
vertices.
If we consider
the land masses A, B, C, and D, the network matrix can be formed:
![]()

The network matrix T and powers of that matrix allow us to
consider other questions:
How many ways can
you get from A to B by crossing one bridge?
How many ways can
you get from A to B by crossing two bridges?
Is it possible to
get from B to C without crossing at least two bridges?
Matrices are useful
when considering large networking problems. Manipulation of the matrices can be
done with technology. Students may research the matrix applications in
networking problems.
Have a class
discussion about how the skills and concepts in this activity could be applied
to the culminating project. Suggest Markov chains, communication matrices,
profit/cost matrices, etc. to show students how they can use matrices to
connect to their projects.
·
Students who work
on these activities might prepare a written report and/or make a presentation
to the class. Students could critique the presentations. (See rubrics in
Appendix B, C, and D.)
Time: 5 hours
At various stages
during the course, students are given opportunities to practise the skills of
presenting and critiquing. The formative assessment provided by the teacher and
peers facilitate success when culminating work is expected.
Ontario Catholic
School Graduate Expectations
CGE5e - respects the
rights, responsibilities, and contributions of self and others;