Partition Numbers to at Least Three Digits

Usual Year Group Learning: Year 1 (2 digits), Year 2 & 3 (3 digits)

Partitioning numbers is breaking down two- or three- digit numbers into their component Hundreds, Tens and Ones (HTO). For example, the number 26 would be broken down into 20 and 6 and sometimes referred to as 2 Tens and 6 Ones. A Hundreds number, such as 837 would be broken down into 800 + 30 + 7.

Spending time on this skill with your child at the cusp of Year 3 and 4 will pay dividends in the future. It’s a skill used frequently in mental maths calculating.

I’m a great advocate of the Concrete-Pictorial-Abstract method of maths teaching, so of course, we have a model for partitioning! It’s called a whole-part model and here it is:

A nice approach to partitioning numbers is to play ‘car games’ and ask questions on a journey with all the family involved. You could even use numbers that you spot when out and about and make it a family tradition.

Essential Knowledge
  • A whole-part model can be used to separate into HTO
  • A whole-part model can be used to share out a number, evenly or unevenly (10 can be partitioned into 4 and 6: more on this later)
What to ask your child
  • How many Tens in 86?
  • Using Deines, can you make 384?
  • Using a whole-part model, can you partition 342?
  • How many different ways can you partition 20? Can you draw three whole-part models to show me?
Useful Resources