43 – 12 =

Remember how we can use partitioning to help us to subtract?

43 – 12 =

First draw the biggest number.

Now cross out the second number to subtract.

Count what is left.

10 20 30

31

43 – 12 = 31

43 – 15 =

First draw the biggest number.

Can we cross out the second number to subtract?

We need to cross out 5 units and we only have 3!

43 – 15 =

We need to cross out 5 units and we only have 3 but how many units are in one ten?

43 – 15 =

Lets break up one ten to make ten units.

43 – 15 =

Now can we cross out 1 ten and 5 units?

43 – 15 =

Now count what is left.

10 20

21

22

23

24

25

26

27

28

43 – 15 =

43 – 15 = 2810 20

21

22

23

24

25

26

27

28

Try some on your own.

34 – 17 =