Multiplication and Division of Decimal Fractions

 

Multiplying decimals is the same as multiplying whole numbers except for the placement of the decimal point in the answer.

Dividing Decimals is the same as dividing whole numbers except the placement of  decimal point in the quotient directly above the decimal point in the dividend.

When you multiply decimals, the decimal point is placed in the product so that the number of decimal places in the product is the sum of the decimal places in the factors.

To divide by a decimal, multiply the divisor by a power of ten to make the divisor a whole number. Then multiply the dividend by the same power of ten. You can think of this as moving the decimal point in the dividend the same number of places to the right as you move the decimal point in the divisor.

Then place the decimal point in the quotient directly over the decimal point in the dividend. Finally, divide as you would with whole numbers.

Example:

Let’s compare two multiplication problems that look similar: 214 x 36, and 21.4x3.6.

214

x  36

1284

6420

=7,704

21.4 

x  3.6

1284

6420

=77.04

Example:

Divide 6.85 by 0.5