Math 6A ( Periods 2 & 5)

Dividing Mixed Numbers 2.3

Dividing a Mixed Number by a Fraction

Write each mixed number as an improper fraction. Then divide as you would with a proper fraction.      Find   

Write   as the improper fraction            so it becomes          

but that becomes    because we multiply by the reciprocal of 3/8 which is 8/3  Simplify first—if you can                = 6

Dividing Mixed Numbers

Find                          ALWAYS ESTIMATE FIRST   4÷ 2 = 2

Write each mixed number as an improper fraction

  but that becomes      or   notice you can simplify so that before you multiply you have       =  

Real Life Application

One serving of tortilla soup is 1 2/3 cups. A restaurant cook makes 50 cups of soup. Is there enough to serve 35 people? Explain your thinking.

Divide 50 by 1 2/3  to find the number of available servings.

      If we simplify first 

There will not be enough to feed 35 people. There is only enough to feed 30 people.

Math 6A ( Periods 2 & 5)

Dividing Fractions 2.2

Two numbers whose product is 1 are reciprocal. 

To write the reciprocal of a number, write the number first as a fraction—then invert the fraction.

so the reciprocal of a fraction        

Dividing Fractions

To divide a number by a fraction, multiply the number by the reciprocal of the fraction.

Examples:
Numbers      

Algebra   

Find                                           

Dividing a Fraction by a Whole Number

Find              Remember:  always invert the 2^nd number – the divisor

so this becomes