Multiplying Decimals www.assignmentpoint.com

Example: 5.63 x 3.7 1 4 2 5.63 two x 3.7 one 1 1 39 4 1 1 + 16 8 9 2 . 8 3 1 three www.assignmentpoint.com

To Multiply: You do not line up the factors by the decimal. Instead, place the number with more digits on top. Line up the other number underneath, at the right. Multiply Count the number of decimal places (from the right) in each factor. Use the total number of decimal places in your two factors to place the decimal in your product. www.assignmentpoint.com

Example: 0.53 x 2.618 2.618 has more digits (4) than 0.53 (3), so it goes on top. 3 4 Decimal Places 1 2 2.618 three x 0.53 two 1 7 8 5 4 13 9 + 00 . 1 3 8 7 5 4 five www.assignmentpoint.com

1 Multiplying Decimals  Multiplying Decimals 5.82 0.41 –––––– ––– EXAMPLE 1 Multiplying Decimals 5.82 2 decimal places 0.41 ––––––  ––– + 2 decimal places 5 8 2 2 3 2 8 ––––––– 2.3 8 6 2 4 decimal places 4 1 3 2 www.assignmentpoint.com

2 Multiplying Decimals  Multiplying Decimals 6.45 –––––– 18 ––– 5160 EXAMPLE 2 Multiplying Decimals 6.45 2 decimal places ––––––  18 0 decimal places ––– + 5160 645 –––––– 116.10 2 decimal places After you place the decimal point, you can drop any zeros at the end of an answer. ANSWER 6.45  18 = 116.1 www.assignmentpoint.com

3 Multiplying Decimals   Multiplying Decimals 6.45 1.273 18 –––––– EXAMPLE 3 Multiplying Decimals 6.45 2 decimal places 1.273 3 decimal places 18 ––––––  0 decimal places ––– + –––––––  0.06 ––– + 2 decimal places 5160 0.0 7638 5 decimal places 645 –––––– 116.10 2 decimal places Write a zero before the 7 as a placeholder so that the number has 5 decimal places. After you place the decimal point, you can drop any zeros at the end of an answer. www.assignmentpoint.com

Try This: 6.5 x 15.3 3 1 2 1 15.3 one x 6.5 one 1 7 6 5 + 9 1 8 . 9 9 4 5 two www.assignmentpoint.com

Multiplication Properties Commutative 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) www.assignmentpoint.co

If a Decimal number is multiplied by 10,100, 1000 etc If a Decimal number is multiplied by 10,100, 1000 etc., the decimal shifts to the right side according to the number of Zeroes. Ex) Multiply 12. 277 x 10 = 122.77 Ex) Multiply 132. 277 x 100 = 13227.7 Ex) Multiply 42. 587 x 10000 = 425870. www.assignmentpoint.com