Y2 - Maths Learning - Week Beginning 13th March 2017

This week in Maths we have been revising our addition and subtraction skills.  We have been using our number bonds last week to quickly add and subtract over 10s boundaries.  For example for addition:
28+6=
We know that we have to add 6.  We also know that if we are at 28 we need 2 more to get to 30.  So we have to use our number bonds for 6. 
2+4=6
So as we have already added to we know that our answer is going to be 4 more than 30.
Using a number line helps to show this or counters to help to see how to add on 2 then 4 more.
For subtraction:
53-7=
We know that we have to subtract 7.  We also know that if we are at 53 we need to take away 3 to get to 50.  So we have to use our number bonds for 7.
3+4=7
So as we have already subtracted 3 we need to subtract 4 more from 50.
Using a number line helps to show this or counters to help to see how to subtract 3 then 4.

We have also been looking at how to calculate subtraction of two digit numbers when the ones are more in the number you are subtracting.
For example:
54-28=
We have begun to understand that we can't swap the order in subtraction so we have to partition the second number to subtract it.
28 is made up of 20 and 8 so:
First take away the tens: 54-20=34
Then take away the ones: 34-8=26
So 54-28=26

Both of these skills are tricky and will take some time to master.  Hopefully you can see how important those number bonds are that we sent home for home learning last week!

This hundred square might help you if you are adding and subtracting at home.