Fractions XIV Multiplication of Fractions by Monica Yuskaitis

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 Copyright © 2000 by Monica Yuskaitis

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 Copyright © 2000 by Monica Yuskaitis

Multiplying Fractions Conceptual 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 Fractions Conceptual 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 Fraction 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 Fraction Step 1 - When you see a fraction problem you know when you read “of” in the problem you multiply. 1 4 x of 2 9 Copyright © 2000 by Monica Yuskaitis

How to Find a Fraction of a Fraction Step 2 – Multiply your numerators straight across. 1 x 4 4 = 2 9 Copyright © 2000 by Monica Yuskaitis

How to Find a Fraction of a Fraction Step 3 – Then multiply your denominators straight across. 1 x 4 4 = 2 9 18 Copyright © 2000 by Monica Yuskaitis

How to Find the Fraction of a Fraction Step 4 – Simplify your answer. In this case we reduce. 1 x 4 4 2 2 ÷ = = 2 9 18 2 9 ÷ Copyright © 2000 by Monica Yuskaitis

Copyright © 2000 by Monica Yuskaitis Multiply and Simplify 1 9 9 3 3 of ÷ x = = 6 5 30 3 10 ÷ Copyright © 2000 by Monica Yuskaitis

Copyright © 2000 by Monica Yuskaitis Multiply and Simplify 8 3 24 12 2 of x ÷ = = 9 4 36 12 3 ÷ Copyright © 2000 by Monica Yuskaitis

Copyright © 2000 by Monica Yuskaitis Multiply and Simplify 4 7 4 28 of x = 6) 28 2 3 6 24 4 2 2 ÷ 4 4 = 4 6 2 3 ÷ Copyright © 2000 by Monica Yuskaitis

Copyright © 2000 by Monica Yuskaitis Multiply and Simplify 3 3 9 27 3 8 of x = 8) 4 2 8 27 24 3 Copyright © 2000 by Monica Yuskaitis

Copyright © 2000 by Monica Yuskaitis Multiply and Simplify 2 7 8 56 9 6 of x = 6) 3 2 6 56 54 2 2 1 ÷ 9 = 9 2 6 ÷ 2 3 Copyright © 2000 by Monica Yuskaitis

Copyright © 2000 by Monica Yuskaitis Multiply and Simplify Super job! 4 4 3 12 1 8 of x = 8) 2 4 8 12 8 4 4 1 ÷ = 1 1 4 8 4 2 ÷ Copyright © 2000 by Monica Yuskaitis

Copyright © 2000 by Monica Yuskaitis Credits Clipart from “Microsoft Clip Gallery” located on the Internet at http://cgl.microsoft.com/ clipgallerylive/default.asp Copyright © 2000 by Monica Yuskaitis