Lesson 11-9

Example 1 Find Reciprocals
Find the reciprocal of 9.

Since 9 ×  = 1, the reciprocal of 9 is .

Example 2 Find Reciprocals
Find the reciprocal of .

Since  ×  = 1, the reciprocal of  is .

Example 3 Divide by a Fraction
Find  ÷ .

 ÷  =  × 	Multiply by the reciprocal, .
          = 	Divide 3 and 6 by the GCF, 3.

Multiply numerators. Multiply denominators.

          = 		 

Example 4 Divide by a Fraction
Find 5 ÷ . 

5 ÷  =  × 		Multiply by the reciprocal of .
         =  or 10	Simplify.

Example 5 Divide by a Whole Number
PLAYGROUND   A playground that is  of an acre is to be divided into 3 equal areas for different types of play. What is the size of each area?

Divide  into 3 equal parts.

 ÷ 3 =  × 	Multiply by the reciprocal.	
         = 	Simplify.	

Each area of the playground will be  acre.