Next week we will be focussing on subtraction. Have a look at these videos. They explain some subtraction methods which you may have used in school. What do you think? Do you have any questions?

There are many ways of doing subtraction and we have to find those that work consistently for us. You need one “go to” method that you would use for most questions because it always works. There may then be other questions that you use other methods for because it is more efficient.

In subtraction there little bit of rules you need to know to do it for example

243

– 156

———

so here you can’t do 3-6 because it will be a negative number so we take from the tens so then it will turn to 13-6=7 so then oh know 3-5 you can’t do it so from the hundreds collum so it will now be 130-50=80 then add 80+7=87

You are growing more and more confident when exchanging.

I find subtraction really easy unless there are missing digits I know what to do with missing boxes though I also know exchanging even if I had 906 – 349=557 but that wouldn’t only exchange once.

906 – 349 = 557 906

_ 349

answer 557

When exchanging remember that you should have space to cross and give to the number when your exchanging you are dividing a number to make the other one

If you have a calculation like this:

327-

13

If you are negative then this sum will be too easy for you to do. But if you are positive and you want to do a even more trickier subtraction for example…

132-

14

and you get confused, dont because you could just borow a 10 from the 3 so the 2 will be 12, but because you added a 10 to the 12 the 3 is now 2 and once you done all this you can now do your calculation easily.

Do we ‘borrow’ or ‘exchange’?

Borrow