Take Away Subtraction

With Regrouping

Base 10 Blocks

Allan and Scott

Problem: 32 - 17

Build 32 on the top portion of the Subtraction Mat.

How many tens? Record it.

How many ones? Record it.

How much is that?

3 2

Write minus seventeen on the middle portion of the mat.

3 2

- 1 7

Is it possible to take away seven ones? (no)

Exchange a ten for 10 ones and place them on the ones portion of the mat.

Record the exchange.

3 2

- 1 7

1 22

Remove seven ones and place them below the line on the small sheet.

23

- 1 7

1 22

How many ones left on the Subtraction Mat? (5)

Pull them to the bottom portion of the Mat and record.

31 222

- 1 7

5

Remove one of the tens and place it below the line on the small sheet.

31 222

- 1 7

5

How many tens left on the Subtraction Mat? (1)

Pull it to the bottom portion of the Mat and record.

31 222

- 1 7

51