Today, in our live lesson, we will be adding two 2 digit numbers by counting on in 10s and 1s.
You will need a 100 square to help you with this. If you do not have one, why not have a go at making your own on a piece of paper
Let's look at the number sentence 34 + 24 =
Find the number on the 100 square. Instead of doing ten little jumps on, remember you can do one big spider jump to the number below and that is 10 more.
For the number sentence 34 + 24 you would do 2 big spider jumps to the numbers below to add the two tens in the number 24. We start on 34, the biggest number, and jump down to 44 to add one ten, then jump down to 54 to add two tens. See the picture below.
To add ones on the 100 square you do one more little jump on. There are 4 ones in 24, So we start at 54, where we landed after adding our tens, and do 4 little jumps across and we land on 58. Our answer is 34 + 24 = 58
Have a go at practising this with the chilli challenges below. If you complete them, you could make up some more of your own number sentences.