Multiplying and Dividing Decimals by Whole Numbers Lesson 3-6: Multiplying and Dividing Decimals by Whole Numbers

Multiplying by whole numbers Multiply decimals as you would whole numbers. Then place the decimal point in the product. The number of decimal places in the product is equal to the sum of the number of decimal places in the factors.

Example: 5.63 x 7 4 2 5.63 two x 7 39 . 4 1 two

Multiplying by 10,100, 1000 ect: When you multiply by 10, 100, or 1,000, you can move the decimal point to the right. The number of decimal places you move is the same as the number of zeroes you are multiplying by. When you divide by 10, 100, or 1,000, you can move the decimal point to the left. Move the decimal point once for each zero you are dividing by.

1.492 x 100 Move the decimal to the right: two spaces. 149.2

2,124.94 ÷ 1,000 Move the decimal to the left: three spaces. 2.12494

4.2 ÷ 100 Move the decimal point to the left: two spaces. Add a zero for the second space. .042

15.36 x 1,000 Move the decimal point to the right: three spaces. Add a zero for the third space. 15,360

Practice P165 # 1-9 odd (check answers in back of text) The above image is a royalty free picture provided by http://www.bigfoto.com