Multiplying Decimals

To Multiply:• Place the number with more digits on top.• Line up the numbers, ignoring the decimal

point. • Multiply• Count the number of digits behind the

decimal in each number. • Use the total number of digits behind the

decimal factors to place the decimal in your product.

Example: 5.63 x 3.7

5.633.7x

1

2

4

4

39098

1

16+13

1

8

1

0

1

2

two

one

three.

Example: 0.53 x 2.6182.618 has more digits (4) than 0.53 (3), so it goes on top.

2.6180.53x

4

2

58

1

700

4

90

3

13000000+457

1

831

Decimal Places

three

two

five.

Try This: 6.5 x 15.3

15.36.5x

5

1

6

2

708

1

1

3

9+54

1

99

one

one

two.

Multiplication PropertiesCommutative Property of Multiplication: Factors can be multiplied in any order.

Example: 12 x 5 = 5 x 12

Associative Property of Multiplication: Factors can be grouped in any way.

Example: (2 x 3) x 5 = 2 x (3 x 5)

Identity Property of Multiplication: The product of any number and one is that number.

Example: 18 x 1 = 18