Odd or even?

We have been looking at odd and even numbers in Room 16. 

Did you know that if a number ends in 0, 2, 4, 6 or 8 then it is an even number. This means every digit has a buddy and no one is left out. But if a number ends in 1, 3, 5, 7 or 9 then it is an odd number. This means that one digit is left out as it has no buddy.

We made predictions, solved the problems in buddies using blocks and came up with conclusions about what happens when you add an even number with an even number. 

 (Can you spot the not so delibrate mistake by Whaea Eve? Room 16 noticed it straight away!)

We did it again for odd plus odd. 

Then odd plus even or even plus odd and it will always give you then same answer, no matter which way you add it. In fact, in Room 16 we try to add from the biggest number. 

This can help us to make predictions when adding big numbers together. So if we solve this problem: 26 + 48, and get the answer 73 then we must have got it wrong as an even number plus an even number = an even number. So we know to go back and check out workings out as we MUST have made a mistake (answer is 74 in case you were wondering!).