Income
Levels & Social Class: is it all about cash?
By Michele Soussou
Suggested
Grade Levels: 5th  8th grades
Suggested
Subject Area: Mathematics
Learning
Objectives:
Students will have the opportunity to:
 Apply understanding of graphing and graph interpretation.
 Apply understanding of percentages and their calculation.
 Set
up a spreadsheet and do calculations using columns.
 Reason from data.
Standards
List:
This
activity addresses the following national content standards
as outlined by the National Council of Teachers of Mathematics,
accessible at http://standardse.nctm.org/1.0/89ces/Table_of_Contents.html:
Standard
1: Mathematics as Problem Solving
In grades 58, the mathematics curriculum should include numerous
and varied experiences with problem solving as a method of
inquiry and application so that students can formulate problems
from situations within and outside mathematics; verify and
interpret results with respect to the original problem situation;
generalize solutions and strategies to new problem situations.
Standard
2: Mathematics as Communication
In grades 58, the study of mathematics should include opportunities
to communicate so that students can model situations using
oral, written, concrete, pictorial, graphical, and algebraic
methods; reflect on and clarify their own thinking about mathematical
ideas and situation; use the skills of reading, listening,
and viewing to interpret and evaluate mathematical ideas;
discuss mathematical ideas and make conjectures and convincing
arguments.
Standard 3: Mathematics as Reasoning
In grades 58, reasoning shall permeate the mathematics curriculum
so that students can recognize and apply deductive and inductive
reasoning; appreciate the pervasive use and power of reasoning
as a part of mathematics; validate their own thinking.
Standard 4: Mathematical Connections:
In grades 58, the mathematical curriculum should include
the investigation of mathematical connections so that students
can explore problems and describe results using graphical,
numerical, physical, algebraic, and verbal mathematical models
or representations; apply mathematical thinking and modeling
to solve problems that arise in other disciplines, such as
art, music, psychology, science, and business; value the role
of mathematics in our culture and society.
Standard 5: Number and Number Relationships
In grades 58, the mathematics curriculum should include the
continued development of number and number relationships so
that the students can represent numerical relationships in
one and twodimensional graphs
Standard 6: Number Systems and Number Theory
In grades 58, the mathematics curriculum should include the
study of number systems and number theory so that students
can understand and appreciate the need for numbers beyond
the whole numbers; develop and use order relations for whole
numbers, fractions, decimals, integers, and rational numbers;
extend their understanding of whole number operations to fractions,
decimals, integers, and rational numbers; understand how the
basic arithmetic operations are related to one another; develop
and apply number theory concepts (e.g., primes, factors, and
multiples) in realworld and mathematical problem situations.
Standard 7: Computation and Estimation
In grades 58, the mathematics curriculum should develop the
concepts underlying computation and estimation in various
contexts so that students can develop, analyze, and explain
procedures for computation and techniques for estimation;
use computation, estimation, and proportions to solve problems;
use estimation to check the reasonableness of results.
Standard 8: Patterns and Functions
In grades 58, the mathematics curriculum should include explorations
of patterns and functions so that students can describe and
represent relationships with tables, graphs, and rules.
Standard 10: Statistics
In grades 58, the mathematics curriculum should include exploration
of statistics in realworld situations so that students can
systematically collect, organize, and describe data; construct,
read, and interpret tables, charts, and graphs; make inferences
and convincing arguments that are based on data analysis;
evaluate arguments that are based on data analysis.
Tools
and Materials:
 Computers with internet access
 Computers with spreadsheet software or calculator and graph paper
 "Mean Income Received by Each Fifth and Top 5% of Families" handout, available at http://www.epinet.org/datazone/01/incfifth.pdf
 Group
Worksheet
(available as a download from this site)
Time
Needed:
It is suggested that one to two 45 minute class periods be used for the lesson.
Strategy:

Have students log onto the Class in America web site at
http://www.pbs.org/peoplelikeus/index.html
Students should click on "STORIES" and read each story.
 After
they read the stories, encourage the students to discuss
what the income levels of each character might be. How would
their income levels affect their lifestyles? Here are some
questions to generate class discussion on social class and
income levels:
 Describe
the lifestyles and living standards of the 20% of the
population with the highest income level in this country.
Now describe the stories and living standards for the
20% of the population that has the middle income level.

Is it possible for people of different income levels to
be part of the same social class?
 If
two families have the same income but make very different
choices about how to spend their money (such as how much
to spend on housing, travel and entertainment, vs. how
much to spend on education, etc.) would they be in the
same social class?
 What
do you think the difference in income level is between
the richest fifth of Americans and the poorest fifth of
Americans?
 Do
you think that in other countries the 20% of the population
with the highest income level has the same lifestyle as
the highest social class in America? Do the poorest 20%
around the world have similar living standards?
 Do
you think the same number of people are in each social
class in each country? In America, does each social class
described in the stories include the same number of people?
 Are
social classes distinct or do you think there are people
who live on the border between classes? What do you think
it would be like to live straddling two classes?

Pass out the sheet "Mean Income Received by Each Fifth and
Top 5% of Families." This is available at http://www.epinet.org/datazone/01/incfifth.pdf.
Here are some questions to encourage discussion: What do
the "lowest fifth", "second fifth" and "highest fifth" refer
to? What class would we label the lowest fifth? Second fifth?
Third fifth? How would you classify the people in the stories?
Is the difference in income between the top and bottom fifths
what they predicted it would be?
 This
is a good opportunity to pick up the pace of the lesson,
with quicker questions that involve a lot of students. Some
of these questions might include: Give a fraction equivalent
to 1/5? Another? How do you know they are equivalent fractions?
What is 1/5 equal to as a decimal? As a percentage? How
do you change fractions into decimals? How do you change
decimals into fractions? How would you write 2/5, 3/5, 4/5
and 5/5 as decimals? As a challenge, how about writing 1/4
as a decimal? 20/80? Can you do any of these quickly or
in your head? What makes them so easy?
 Divide
the class into cooperative groups and pass out Group Worksheet
(available as a download from this site). Have the students
work on it in groups.

Bring the class back together and lead the discussion as
the students compare their results. Try to generate discussion
on the cost of living and how it varies across years and
regions. You might pose the following questions: Why were
all of the numbers on the sheet "Mean Income Received by
Each Fifth and Top 5% of Families" reported in 1997 dollars?
Is $30,000 always worth the same amount? Does a car cost
the same today as 10 years ago? A house? A gallon of milk?
Are prices the same across the country?

Go to the web site http://newsengin.com.
Look under Free Tools and the Cost of Living Calculator.
There are sections titled "Background: How the Cost of Living
Calculator Works" and "Details: How The Government Measures
Changes in Consumer Prices." These are good background sections.
They include the formula that the calculator uses to find
the change in prices. Read these before class. There are
two calculators. One includes all items and the other includes
all items less food and energy. You can also choose whether
to look at a U.S. average or a particular city.

Let the students play with the calculators in small groups

Once they have the chance to play with it, explain the background
and how the CPI calculator works. You might pose the following
questions: Why are there different calculators for different
cities? Have the students graph how much $100 in 1950 (or
choose another year) in different cities would have as buying
power in 1999. Lead a discussion on why the same $100 is
worth different amounts in different cities in 1999.
Assessment
Recommendation:
 Students can be evaluated on the accuracy of their responses in the group discussion and on their level of participation in the class discussion.
 Students
can be evaluated on the accuracy of their responses on the
Group Worksheet.
Extensions:
Comparison of different regions and states:
 Log on to http://epinet.org
 Go to the section titled State & Regional Data. Under Family Earnings and Income Trends
there are tables titled "Income Inequality by State" and "Median Income for FourPerson Families".
 Assign each student or group a different region and have them answer questions about their region:
 For income inequality: What does the 6.7 for Maine in 197880 mean? Are trends getting better or worse in Maine when it goes to 7.7 in 198890?
 Ask the students to think about why the income gap is shrinking or growing in their state. What factors could be contributing to the change?
 For median income: Have the students explain the difference between median and mean, which was used in the activity sheet. Graph the median incomes by state for 1996. What are some factors that would cause certain states to have high median incomes? Very low median incomes? Is the cost of living the same across the country?
Budgeting
extension activity:
 Divide
the class into groups.
 Assign
each group a different size family. For example, one group
could represent a family with two parents and two children,
another could represent a single parent and child or a single
person. Have each group prepare a monthly budget for their
family based on a monthly income of $3,714 dollars ($44,568
annually). Each family has the same income level (although
it is also possible to assign groups different income levels
in addition to different family sizes). Specify which city
the students should use as the hometown.
 Have
all the students brainstorm as a group to think up a list
of categories that should be included in a budget. Make
sure their list includes at least these categories:
 Housing
 How big a house or apartment? Is it near a good school?
Any amenities with the apartment?
 Utilities
 phone basic service or include call waiting and caller
ID? Gas, electricity...
 Car
 what kind of car? Insurance, gas, maintenance...
 Clothes
 Food
 groceries and restaurants
 Entertainment
 travel, movies...
 Have
the students use sources such as the web and newspapers
to find realistic prices.
 Afterwards
have each group present their budget to the class. The presentation
should include a pie chart to show how the monthly income
is split between to budget categories.
 Discuss
how the budget choices change depending on the size of the
family and income level. Compare the pie charts for the
groups. Is the split between categories similar for each
group? For each income level? Students might also work with
spreadsheets when building their budgets.
 Have
students research mean incomes in other nations and prepare
a chart comparing mean incomes in other countries to the
mean income in the United States. In a group discussion,
students could brainstorm about why some countries might
have a higher or lower mean income than we do Ð i.e. what
factors affect the statistics. Explanations might include
things like the high population density in certain oilproducing
nations, postcolonial underdevelopment, etc.
download the PDF version
download the worksheet 