In translating sentences into mathematical expressions, the term "of" represents multiplication and the term "is" represents the equals sign.  

  Note: We use the variable N to represent the number we are looking for, also called the unknown.

Example: 30% of 90 is what number?


.30 x 90 = N

(note: we changed the percent to a decimal)

27=N


Therefore the number is
27.

 

 

Example: 30% of what number is 90?


.
30 x N = 90

(again, change the percent to a decimal)


N = 90 ÷ .30

(divide each side by .30)


N = 300

Therefore the number is 300.

Example: What percent of 90 is 30?


P x 90 = 30


P = 30 ÷ 90

(divide each side by 90)


P = .333…


P = 33.3% (change the decimal to a percent)

 

What is Zippy Joe's yearly expenses?

There are 52 weeks in a year.

$

Max Speedo races in the Motordrome Circuit in Radiant City Prime. There are 180 races every season. The winner of the season is declared Circuit Champion and given the secret code to the Tower of Power.  

 How many more races did he win in his new Zoomer?

main | proportions
 

  writer:Kevin Gallagher