1. Multiplication of Fractions

2. Copyright © 2000 by Monica Yuskaitis

3. Why would I need to multiply a fraction by a another fraction?

4. You and your friends ate ½ of the 8 cookies that were in the jar
You and your friends ate ½ of the 8 cookies that were in the jar. How many cookies did you eat? 4
1 2 of 8 =

5. You won 1 4 of the 20 remaining cards during a card game
You won of the 20 remaining cards during a card game. How many did you win? 5
1 4 of 20 =

6. Let’s try some trickier ones!!
Today your family ate of of the leftover birthday cake from your 12th birthday. How much of the original cake did your family eat today?
1 6
1 3 of =

7. Challenge!!!!
Andy already read of his novel. Today he read of the remaining half of the book. How much of the book has he read in total?
1 24
1 12 of =
1st Step:
13 24 =
2nd Step:

8. 1 2 of = 3 8
1 4
1 4
1 4
1 4
1 8
1 8
1 8

9. How to Find a Fraction of a Fraction
The first thing to remember is that the word “of” means to multiply. of x =

10. Multiplying Fractions1 2 4 4 2 x ÷ of = = 2 9 18 2 9 ÷
Step 1: If necessary, change the “of” to a multiplication sign.
Step 2 – Multiply your numerators.
Step 3 – Multiply your denominators.
Step 4 – Simplify your answer. In this case we reduce.

11. Multiply and Simplify 1 9 9 3 3 of ÷ x = = 6 5 30 3 10 ÷

12. Multiply and Simplify 8 3 24 12 2 of x ÷ = = 9 4 36 12 3 ÷

13. Multiply and Simplify 7 4 28 4 of x 4 = = 2 3 6 6 2 4 = 3

14. Multiply and Simplify 3 3 9 27 of x = 3 = 4 2 8 8

15. Multiply and Simplify 7 8 56 2 of x 9 = = 3 2 6 6 1 = 9 3

16. Shortcut: You can simplify before multiplying by cross cancelling!!!3
1.) Choose any one numerator and any one denominator that share a common factor and cross them out.
2.) Divide by the common factor and write down the new numerator and denominator.
3.) Multiply.
*You may do this twice for each problem, if possible. 1 9 3 of x = 6 5 10 2

17. Cross Cancel 1 2 8 3 2 of x = 9 4 3 3 1

18. Cross Cancel 2 7 4 14 2 of x 4 = = 2 3 3 3 1

19. Cross Cancel and Multiply
Super job! 1 4 3 3 of x = 2 4 2 1 1 1 = 2