Fractions Fractions Multiplication of FractionsMultiplication of Fractions

Copyright © 2000 by Monica Yuskaitis

Times You Would Multiply a Times You Would Multiply a Fraction Times a FractionFraction 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

Copyright © 2000 by Monica Yuskaitis

Times You Would Multiply a Times You Would Multiply a Fraction Times a FractionFraction 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

Copyright © 2000 by Monica Yuskaitis

Multiplying FractionsMultiplying FractionsConceptual UnderstandingConceptual 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.

Copyright © 2000 by Monica Yuskaitis

Multiplying FractionsMultiplying FractionsConceptual UnderstandingConceptual Understanding

½ x ¾ = 3/8 ¼ ¼ ¼ ¼

1/8 1/8 1/8

Copyright © 2000 by Monica Yuskaitis

How to Find a Fraction of a How to Find a Fraction of a FractionFraction

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

of = x

Copyright © 2000 by Monica Yuskaitis

How to Find a Fraction of a How to Find a Fraction of a FractionFraction

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

ofx12

49

Copyright © 2000 by Monica Yuskaitis

How to Find a Fraction of a How to Find a Fraction of a FractionFraction

Step 2 – Multiply your numerators straight across.

x 49

12 = 4

Copyright © 2000 by Monica Yuskaitis

How to Find a Fraction of a How to Find a Fraction of a FractionFraction

Step 3 – Then multiply your denominators straight across.

x 49

12 = 4

18

Copyright © 2000 by Monica Yuskaitis

How to Find the Fraction of a How to Find the Fraction of a FractionFraction

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

x 49

12 = 4

18÷÷

22= 2

9

Copyright © 2000 by Monica Yuskaitis

Multiply and SimplifyMultiply and Simplify

95

16

= 930 10

3ofx ÷÷

33

=

Copyright © 2000 by Monica Yuskaitis

Multiply and SimplifyMultiply and Simplify

34

89

= 2436 3

2ofx ÷÷1212

=

Copyright © 2000 by Monica Yuskaitis

Multiply and SimplifyMultiply and Simplify

43

72 = 28

6 6)284ofx

2444 4

6÷÷22 = 2

34

Copyright © 2000 by Monica Yuskaitis

Multiply and SimplifyMultiply and Simplify

92

34 = 27

8 8)273ofx

243

38

Copyright © 2000 by Monica Yuskaitis

Multiply and SimplifyMultiply and Simplify

82

73 = 56

6 6)569ofx

542

26

9 26

÷ 22

=9 13÷

Copyright © 2000 by Monica Yuskaitis

Multiply and SimplifyMultiply and Simplify

34

42 = 12

8 8)121ofx84

48

1 48

÷ 44

= 1 12÷

Super job!