Remember how we can use partitioning to help us to subtract? 43 – 12 =

First draw the biggest number. 43 – 12 = First draw the biggest number. Now cross out the second number to subtract. 31 Count what is left. 10 20 30 43 – 12 = 31

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

Lets break up one ten to make ten units. 43 – 15 = Lets break up one ten to make ten units.

Now can we cross out 1 ten and 5 units? 43 – 15 = Now can we cross out 1 ten and 5 units?

43 – 15 = 25 21 24 26 22 27 23 28 10 20 Now count what is left.

43 – 15 = 25 21 24 26 22 27 23 28 10 20 43 – 15 = 28

Try some on your own. 34 – 17 =