6th Grade Math Textbook, Fundamentals

 &KDSWHU

7-8

Method 1 Write an Equation

percent increase 

Let RIthe percent increase.

RI

RI Divide to simplify.

RI2.32 Round the decimal to the nearest hundredth.

RI232% Multiply the decimal by 100 to write as a percent. Write the % sign.

4.4

1. 9

Subtract the original amount from the new amount

to find the amount of increase. Substitute 6.3 for

the new amount and 1.9 for the original amount.

6.3 1. 9

1. 9

amount of increase

original amount

Method 2 Write and Solve a Proportion

Let nthe unknown percent increase.

6.3 1.9 4.4





440 1. 9n

 Divide both sides by 1.9. Round to the nearest one.

232 n

So the percent increase in the value of world exports from 1985 to 2000 was about 232%.

1. 9n
   
   
   1. 9
   
   
   
   

440

1. 9

Substitute 4.4 for the amount of increase

and 1.9 for the original amount. Cross multiply.

n

100

4.4

1. 9

percent increase (%)

100

amount of increase

original amount

Subtract the original amount from the new amount

to find the amount of increase.

part

whole

Update your skills. See page 408 III.

Percent Increase

Objective To find the percent increase •To find profit •To find the

selling price for an item sold at a profit

According to the United Nations Department of
Public Information, world exports had a total value
of $1.9 trillion in 1985. Fifteen years later, world
exports had a total value of $6.3 trillion. About what
percent increase was there in the value of world
exports from 1985 to 2000?

To find the in the value of world
exports, compare the amount of increase to the
original amount.

You can use the formula or a proportion

to find the percent increase. Notice that since

both amounts in the problem are in trillions,

the nonzero digits can be used to calculate

the percent increase.

percent increase

Key Concept

Percent change is the ratio comparing a

change in a quantity to the original amount.

A change in a number or a quantity is an

increase or a decrease.

percent change 

Percent Change

amount of change

original amount