How can counting on help me add two-digit numbers?

Snoot and Fin work out how to add their money together to buy blobs.

How can I add two-digit numbers?

Adding two-digit numbers can be tricky.

One way to do it is by counting on.

This is easier if you count on in tens first and then count on in units.

Example

40 + 35 = ?

Count on in tens. 30 is three tens. 40, 50, 60, 70

Now we need to count on in units. There are five units. 70, 71, 72, 73, 74, 75

So 40 + 35 = 75

Did that work for you?

Which way round should I add two numbers?
video
How can reordering numbers into number bonds help me add them?
video
Find more 1st Level resources from BBC Bitesize