Number decomposition is just a fancy way of saying “understanding different combinations that make the same number”.
The number three, for example, has four different ways it can be made:
- 3 + 0
- 2 + 1
- 1 + 2
- 0 + 3
Test your child’s numerical understanding by doing the following:
Take 3 similar items and ask your child to tell you how many you have in your hand. If they answer immediately you can move on to a higher number.
Take 5 similar items and ask your child to tell you how many you have in your hand. If they stop to count them one by one, they do not understand the number.
For the example we are using, you would now move back to 4 and test your child’s understanding of this number. If they can immediately identify 4 you can start at 5. If, however they also have to count the 4 items separately, you should start at 4.
Download the activity pack and help your child improve their numerical understanding. You will need the printed pages and either building blocks in two colours (counters can also work).