Comparing Costs - Texas Instruments TI-15 Teachers Manual

Comparing Costs

Overview
Students will solve a problem using division with an
integer quotient and remainder, division with the
quotient in fraction form, and division with the
quotient in decimal form and compare the results.
Introduction
1. Introduce the following problem:
The maintenance department has determined
that it will cost $.40 per square yard to
maintain the district's soccer field each year.
The soccer field is 80 yards wide and 110 yards
long. The six schools that play on the field have
decided to split the cost evenly. How much
should each school contribute to the soccer field
maintenance fund this year?
2. Have students use the calculator to solve this
problem in three ways:
Finding an integer quotient and remainder.
Finding the quotient in fraction form.
Finding the quotient in decimal form.
Collecting and Organizing Data
Students should record their procedures and results
on the Student Activity page. To help them focus on
their thinking, ask questions such as:
What did you enter into the calculator to solve
the problem?
Example:
A student may have entered
determine the area of the soccer field, then
entered V
0.40
cost, then W
school in fraction or decimal form.
© 2000 T I
EXAS NSTRUMENTS
V
80 110
® to find the total maintenance
® to find the cost for each
6
I
NCORPORATED
Math Concepts
• division
• multiplication
• fractions
• decimals



® to
TI-15: A Guide for Teachers
Grades 3 - 5
Materials
• TI-15
• pencil
• student
activity
(page 14)
To display an integer
quotient with a
remainder, use the £
key.
To display a quotient in
fraction form, press ‡
" ® to select n/d,
then use the W key.
To display a quotient in
decimal form, press
.
‡ ! ® to select
,
then use the W key.
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