> Multiply and Divide by Powers of 10 <

 

Multiply and Divide by Powers Of 10

We can use powers of 10 to multiply and divide
numbers.

 

Multiply a whole number by a power of 10

Add on as many 0's as appear in the power.


To multiply by 10, move the decimal 1 place to the right.
Examples.    47 × 10   =  470

To multiply by 100, move the decimal 2 place to the right.
Example.    47 × 100   =  4700

To multiply by 1000, move the decimal 3 place to the right.
Example.    47 × 1000   =  47000

 

Multiply decimals by a power of 10

Move the decimal point to the right as many places as there are
zeros.


To multiply by 10, move the decimal 1 place to the right.
Example.    5.68 × 10   =  56.8

To multiply by 100, move the decimal 2 place to the right.
Examples.    5.68 × 100   =  568

To multiply by 1000, move the decimal 3 place to the right.
Example.    5.68 × 1000   =  5,680

 

Dividing Whole Numbers by Powers Of 10

Start from the right of the whole number, move the decimal point to the
left as many places as there are zeros in power. Add zeros if not
enough places.

To divide by 10, move the decimal 1 place to the left.
Example:  347 ÷ 10 = 34.7

To divide by 1000, move the decimal 3 place to the left.
Example:  347 ÷ 1000 = .347

 

Dividing Decimals by Powers Of 10
Move the decimal point to the left as many places as there are zeros
in power. Add zeros if not enough places

To divide by 100, move the decimal 2 place to the left
Example:  34.7 ÷ 100 = .347

To divide by 1000, move the decimal 3 place to the left.
Example:  34.7 ÷ 100 = 0.347