Multiplication of

Fractions

Times You Would Multiply a Fraction Times a Fraction

• Your family eats 1/8 of 1/2 of a left over wedding cake. 1/8 of 1/2 or 1/8 x 1/2

Times You Would Multiply a Fraction Times a Fraction

• Jose had already read 1/2 of his novel. Today he read 1/12 of the 1/2 left. How much of the book has he read?

1/12 of 1/2 or 1/12 x 1/2

Multiplying FractionsConceptual Understanding

• When you multiply two fractions that are between 0 and 1 the product is smaller than both fractions.

½ x ¾ = 3/8 Look at the diagram on the next slide to understand why.

Multiplying FractionsConceptual Understanding

½ x ¾ = 3/8 ¼ ¼ ¼ ¼

1/8 1/8 1/8

How to Find a Fraction of a Fraction

• The first thing to remember is “of” means multiply in mathematics.

of = x

How to Find a Fraction of a Fraction

• Step 1 - When you see a fraction problem you know when you read “of” in the problem you multiply.

ofx12

49

How to Find a Fraction of a Fraction

• Step 2 – Multiply your numerators straight across.

x 49

12 = 4

How to Find a Fraction of a Fraction

• Step 3 – Then multiply your denominators straight across.

x 49

12 = 4

18

How to Find the Fraction of a Fraction

• Step 4 – Simplify your answer. In this case we reduce.

x 49

12 = 4

18÷÷

22= 2

9

Multiply and Simplify

95

16 = 9

30 103x ÷

÷33 =

Multiply and Simplify

34

89 = 24

36 32x ÷

÷1212=

Multiply and Simplify

43

72 = 28

6 6)284x

2444 4

6÷÷22 = 2

34

Multiply and Simplify

92

34 = 27

8 8)273x

243

38

Multiply and Simplify

82

73 = 56

6 6)569x

542

26

9 26

÷ 22 =9 1

3÷

Multiply and Simplify

34

42 = 12

8 8)121x84

48

1 48

÷ 44

= 1 12÷

Reference:Yuskaitis, Monica. (2000) Retrieved fromhttp://portal.bentonvillek12.org/athurman/5th%20Grade%20Math/Module%205/Multiplication%20of%20mixed%20numbers.pdf