To multiply decimals mentally by 10, 100 and 1000

Multiply.

To multiply by 10, move all the digits one place to the left               

To multiply by 100, move all the digits 2 places to the left

To multiply by 1000 move all the digits 3 places to the left

Divide

To divide by 10, move all the digits one place to the right

To divide by 100, move all the digits 2 places to the right

To divide by 1000 move all the digits 3 places to the right

 

Remember

Write the place value columns to help.

The decimal point never moves

When  dividing  the number is Reduced and the digits move to the Right.

When multiplying the number gets Larger and the digits move to the Left

Number of zeros is the clue to the how many places to move.

Remember to put zeros as place holders in any columns left empty.                                   

Remember each place value column is 10 times larger than the last when you move to the left and 10 times smaller as you move to the right.