In this activity, we will be multiplying numbers by 10 or 100.

 

To multiply a whole number by 10: move each digit one place to the left, then fill any empty places with zero.

43 × 10 = 430

654 × 10 = 6,540

70 × 10 = 700

 

To multiply a whole number by 100: move each digit two places to the left, then fill any empty places with zero.

43 × 100 = 4,300

60 × 100 = 6,000

542 × 100 = 54,200

 

 

Let's try some examples together. 

 

Example 1

Multiply 65 by 10.

 

Answer

To multiply by 10, each digit moves one place to the left. 

 

In 65, we have 6 tens and 5 ones. 

The 6 tens become worth 6 hundreds. 

The 5 ones become worth 5 tens. 

We fill the ones place with zero as a placeholder.

 

65 × 10 = 650

 

Example 2

Multiply 24 by 100.

 

Answer

To multiply by 100, each digit moves two places to the left. 

 

In 24, we have 2 tens and 4 ones. 

The 2 tens become worth 2 thousands.

The 4 ones become worth 4 hundreds. 

We fill the ones and tens places with zeros as placeholders.

 

24 × 100 = 2,400

 

Now that you know how to multiply by 10 and 100, you are ready to try the next ten questions.