Multiplying by 10's

Multiplying by 10's, 100's, 1000's

Multiplying by Tens

When you multiply by 10's break it into smaller problems.

For example: 20 x 4= (2 x 4) x 10.

Why do we separate the 10?

20 x 4 = ?

We know 2 x 10 = 20

We split 20 into 2 and 10

Then, we multiply 2 x 4 = 8

Then, we multiply the answer by 10. 8 x 10 = 80

Let's Practice!

Multiple Choice

5 x 30 = ( _ x _) x _

• (5 x 3) x 1

• (5 x 3) x 10

• (5 x 30) x 10

Multiple Choice

4 x 60 = ( _ x _ ) x _

• ( 4 x 6 ) x 1

• ( 4 x 60 ) x 10

• ( 4 x 6 ) x 10