Number Bonds to 10 (Part 1)

We've covered basic addition using the standard methods (blocks, fingers, number lines, etc.) and the twins understand the principles, but I wanted their mental arithmetic to be quicker... So decided now was a good time to start getting them familiar with the number bonds to 10, i.e. which pairs of numbers add together to make the number 10.

I gave them each a piece of A4 paper with 10 squares (each the size of a Multilink Cube) down one side, a pencil, 10 cubes of one colour and 10 cubes of another. They had to see how many different ways of making 10 they could find, the two colours being to make the process visually easier.

Both of them decided to start with 5 of each cube and I modelled how to write the number sentence 5 + 5 = 10 on the whiteboard for them to copy onto their paper: handwriting practise as well as a way of keeping a record of their findings along with reinforcement of how sums are displayed. 😄

Now came the tricky part! I removed all the blocks of the second colour and modelled how they didn't have to have 5 of the first colour. Maybe there could be one less, or a couple more, or even none! So I had removed all the blocks completely. So what did they want to try next? I tried to keep it quite open so they were doing more exploring and thinking for themselves.

One decided to make the first colour one more, and ended up doing the task quite systematically. She found all 11 combinations quicker than her sister and it was easy to explain to her how she hadn't missed any out. The other took a more random approach, but she was determined and I could see she was really thinking about which combinations she hadn't tried yet. When she got to her 8th possibility she wasn't sure if she could find any more, so I read through her work in numerical order, using the first number in the sum as a reference, and purposefully paused at the possibilities she missed - she caught on quickly what she needed to try next and that she had 3 more sums to write.

With this activity, it was also nice to see that they remembered some of the addition work we'd done previously, as even before they'd filled in the squares with the second colour cube, they would already guess (most of the time correctly!) at how many more cubes were needed.

Because they worked through finding out what the number bonds were for themselves, rather than just being told them or being made to memorise them parrot-fashion from flashcards, I think it made the pairs stick in their heads more easily. After a break, we practised some mental arithmetic again and they were both noticeably quicker in finding the answers. 😊