Multiplying Decimals & Properties of Multiplication Christine Berg Edited By V T Hamilton

Multiply as if the factors were whole numbers Step 1: Multiply as if the factors were whole numbers

Step 1: 8.5 X2.5 4 2 5 1 7 0 0 2 1 2 5 next…..

Count the total decimals places in the factors Step 2: Count the total decimals places in the factors

Step 1: 8.5 X2.5 4 2 5 1 7 0 0 2 1 2 5 next…..

Give the product the total decimal places of the factors Step 3: Give the product the total decimal places of the factors

Step 1: 8.5 X2.5 4 2 5 1 7 0 0 2 1 .2 5

Try These: 1. 4.8 2. 3.55 x 0.5 x .05

Answers: 1. 4.8 2. 3.55 x 0.5 x .05 = 2.40 = 0.1775

Properties of Multiplication

The product of 1 and a number (a) is the number (a) Identity Property The product of 1 and a number (a) is the number (a) 1(a) = a

Examples 1 (b) = b 1 x 42 = 42

The product of 0 and a number (a) is 0 Zero Property The product of 0 and a number (a) is 0 0 (a) = 0

Examples 0 (b) = 0 0 x 67 = 0

Changing the order of the factors does not change the answer Commutative Property Changing the order of the factors does not change the answer

Examples a ( b ) = b ( a ) 5 x 2 = 2 x 5

Changing the grouping of factors does not change the answer Associative Property Changing the grouping of factors does not change the answer

Examples ( a b ) c = a ( b c ) ( 3 x 2 ) x 4 = 3 x ( 2 x 4 )

Try These: Identify the property ( x y ) z = x ( y z ) 0 x 4 = 0

Answers: ( x y ) z = x ( y z ) Associative Property of x 0 x 4 = 0 Zero Property