Speaker: Addition is the process of adding 2 or more numbers or amounts together to get a total.

If I start on the ground floor I've got to go up 9 floors to get to the top.

That's 0 add 9, which equals 9.

But if I start on the 2nd floor I've only got to go up 7 floors to get to the 9th floor.

Speaker: Often, you can add up different numbers and still get the same answer.

So 2 + 8 + 10 = 20.

So does 4 + 4 + 4 + 4 + 4.

And 10 + 5 + 5 does too.

They all still add up to 20.

There is more than one way to get to the same total.

Just think about all the different ways you can make up £20.

Speaker: I need to work out how many glasses are being brought back.

I'm sure some will be missing; there are always a few lost or broken.

There should be 20 in each box.

I need to check how many I've got now.

So if you're adding 17 and 19, I move 1 of the glasses, so I have a full box of 20.

Then I think it's easier to add 20 and 16 to get 36.

Now I need to add up all the wine glasses I've collected today.

I got 19 and 37 this morning and then 58 and the 36 this afternoon.

9 add 7 is 16, add 8 is 24, add 6 is 30.

That's a 0 in my units column with 3 to carry over.

Then, 12 in my tens column, plus the 3, that's 150 exactly.