Grade 4 - Progress in Mathematics

Use the formula to Draw a picture to

check your answer. check your answer.

Visualize the facts of the problem

as you reread it.

Facts: width 
 3 ft

perimeter 
14 ft

Question: How long is the sign?

Kim is making a rectangular sign that is

3 ft wide. She uses 14 ft of edging to go

around the sign. How long is the sign?

Problem-Solving Strategy:

More Than One Way

14-7

There is more than one way to find

a solution. Here are 2 ways.

Method 1 Method 2

Draw a picture. Use a formula.

P
 2 
 2 w

Guess and test to find Guess and test to find

the length. the length.

First Guess 3 ft Let 

length

3 ft3 ft3 ft3 ft
12 ft P 
 2  
  2 w

not large enough 14 
 2  
 (2 3 ft)

14 
 2  
 6 ft

Second Guess 4 ft 14 
 2  ft6 ft

3 ft3 ft4 ft4 ft
14 ft

14 
 2  4 ft 6 ft

correct sum

The sign is 4 ft long. The sign is 4 ft long.

?

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