LESSON PLAN (Linda Bolin) - Granite School District

LESSON PLAN (Linda Bolin)
Lesson Title: Solving Problems With Proportions
Course: Math 7 Date: Jan Lesson 6
Utah State Core Content and Process Standards:
2.1c Solve problems involving proportions
Lesson Objective(s): Students will solve a variety of problems using proportions.
Enduring Understanding (Big Ideas):
Proportions can be used to solve a
variety of problems.
Skill Focus:
Set up and solve proportions. Work with
percent
Essential Questions:
• How can a proportion be used to solve a
problem?
Vocabulary Focus:
Ratio, proportion
Materials:
• Foldable: Solving Proportions
• Calculators
• Worksheets: Solving Proportions
Assessment (Traditional/Authentic): observation, performance task, journal
Ways to Gain/Maintain Attention (Primacy): graphic organizer, game, technology
Written Assignment
Journal Foldable: Solving Proportions
Worksheet: Solving Proportions
Board Race Record
Appropriate text practice
Starter:
Content Chunks
1. Which are proportions?
A. _2_ ? _4_ B. _3_ ? _9_ C. _1.5_ ? _6_
15 30 7 14 4.5 18
2. What number should n represent: _n_ = _5_
20 100

Lesson Segment 1: How can a proportion be solved?
We know we can recognize two ratios that form a proportion by dividing each to
determine if the quotients are equivalent. There is another way we can recognize a
proportion. Show students how to find cross products in a proportion by having them
find cross products on the Starter questions. Then show them how to solve # 2 on
the starter using cross products rather than using guessing and checking.
Board Race Game: Make a space for each of 8 or 9 teams to write on the board.
Number students on a team 1-4. Put a proportion for the class to solve on the
overhead. Students work together using the cross products method for setting up
and solving the proportion equation. After they have had a chance to work on the
problem with their team or partner, say, “Person # 3, GO”! The person on each team
who is that number quickly moves to the space you have made for the team on the
board, sets up the problem, solves, and checks it. Then, the person moves quickly
back to their seat. Note the first four to finish. When all have returned to their seats,
have class look to see who worked the problem correctly. Give a point to any of the
first four completed, who have correctly worked the procedure. Repeat with another
problem, this time calling a different student number to come to the board, etc.
Lesson Segment 2: How can a proportion be used to solve real-world
problems?
Students use Smart Pals and the reading strategy to set up and solve the problems on
the “Proportion Problems” worksheet. Once the Smart Pals have been shown to the
class, have them record the problem on their worksheet. Reading Strategy: Have
students each read a problem and share with a partner what they think is, a) the key
information in the problem, and b) what the question is asking them to find. Ask two
pairs to their share ideas with class for each problem. Once students have identified
key information and the question, the teacher should do a think-aloud modeling how
to determine what information will be placed in what position on each ratio to form a
proportion.
Journal: Make the Solving Proportions Foldable with the students. This is a center
fold, where the two outside quarters fold toward the center to make doors.
Assign appropriate text practice

Proportion Problems
Name__________________
Instructions: Set up proportions to solve these problems.
1. Mr. Daniels drove 336 miles in eight hours. If he maintains this same speed, how
many miles can he drive in 14 hours?
2. An airplane travels 975 miles in three hours. How many hours will it take to go
1300 miles?
3. An umpire records five hits for every twelve boys at bat. If 180 boys come up to
bat, how many hits should be made?
4. On a trip of 768 miles, Tonie used 48 gallons of gasoline. How many gallons
would be needed to go 1168 miles?
5. If Mario earns $51 in three weeks, how many weeks will it take him to earn 852?
6. 2700 bricks are needed to build 300 square feet of a wall. How many bricks will
be needed to build 1800 square feet of wall?
7. If it takes ten people six hours to assemble 100 Walkmans, how long would it
take them to assemble 500 Walkmans?
8. Two out of five high school graduates attend college. If three hundred seventyfive
graduate, how many will attend college?

Step # 1
First Ratio
Step # 2
Second Ratio
Step # 3-
Solve an Equation
Step # 4-Check
and Answer
Read the problem
carefully!
Look for two
numbers to compare
as the first ratio.
You need three parts
water for one part
orange juice
concentrate.
If you have 12 cups
of water in a pitcher,
how much O.J.
concentrate do you
need?
(__) parts water,
1 part O.J.
Find a third number that is
representing the same kind of
idea as one of the numbers in
your first ratio.
Write a second ratio by
placing this number in the
same position you wrote it on
the first ratio (numerator or
denominator). Put a variable
on the second ratio in the
other position (numerator or
denominator).
water (__) = (__) water
O.J. 1 j O..J.
Multiply to get cross
products that are equal.
Solve the new equation.
( ) ( )
( ) ( )
3j = ( )
_3_ j = (__)
3 3
j = ( )
Substitute the
solution of the
equation to check.
Make sure both
quotients or cross
products are equal.
Answer the
question.
_3_ = (__)
1 ( )
3( ) = 1( ) °
___ cups of
O.J concentrate
are needed.

Step # 1
First Ratio
Step # 2-Second Ratio
Step # 3-
Solve an Equation
Step # 4-Check
and Answer
Read the problem
carefully!
Look for two
numbers to compare
as the first ratio.
You need three parts
water for one part
orange juice
concentrate.
If you have 12 cups
of water in a pitcher,
how much O.J.
concentrate do you
need?
( 3) parts water,
1 part O.J.
Find a third number that is
representing the same kind
of idea as one of the numbers
in your first ratio.
Write a second ratio by
placing this number in the
same position you wrote it on
the first ratio (numerator or
denominator). Put a variable
on the second ratio in the
other position (numerator or
denominator).
water (3 ) = (12) water
O.J. 1 j O..J.
Multiply to get cross
products that are equal.
Solve the equation.
( 3 ) ( 12 )
( 1 ) ( j )
3j = (12 )
_3_ j = (12)
3 3
j = ( 4 )
Substitute the
solution of the
equation to check.
Make sure both
quotients or
cross products
are equal.
Answer the
question.
_3_ = (12 )
1 ( 4)
3(4) = 1(12) °
_4_ cups of
O.J concentrate
are needed.

Proportions
Solving