Dividing Decimal Numbers by 10, 100, 1000 and Multiplying by an Integer

Great job! You have decided to spend some time practising for the SATs arithmetic test.

 

In this activity, you will divide decimal numbers by 10, 100 and 1000.

You will then move onto rehearsing how to multiply decimal numbers by an integer.

 

Example 1: Dividing by 10, 100 and 1000

 

Once you can multiply a decimal number by 10, 100 and 1000, you can then move onto practising how to divide by 10,100 and 1000.

Remember that 0 is always the place holder.

Also, remember that 3.4 is the same as 3.40 and 11.0 is the same as 11

 

When we divide a number, we move the digits to the right.

Look at the place value chart below, it shows 22.12 ÷ 10 = 2.212

Each digit has been moved one place to the right.

 

 

22.12 ÷ 10 = 2.212....All of the digits have moved one place to the right. 

22.12 ÷  100 = 0.2212....All of the digits have moved two places to the right. 

22.12 ÷ 1000 = 0.02212....All of the digits have moved three places to the right. 

 

The decimal point does not move.

 

Example 2: Multiplying Decimals by Integers

When you multiply a decimal number by an integer, you may choose to use the column or grid method of multiplication.

Grid method:

 

Here is the same calculation, solved using the column method:

 

Now, over to you to try some of the practice questions...good luck!