## Year 1: Unitising

How can you quickly work out the number of eggs contained in a stack of egg boxes, or how could you work out the value of a pile of 20p coins?

One way to do it is to count the boxes, or the coins and then do a multiplication.

The mathematical term for working in this way is called, ‘unitising’.

It means treating groups that contain the same number of things as ‘units’ or ‘ones’. The egg box containing six eggs is treated as a one. Working with money is a good example of unitising. It involves the understanding that one coin may not represent a value of one. A 20p coin is treated as a one. A 20p coin, for example, has the same value as twenty 1p coins, and therefore a collection of 20p coins can be counted in 20s. This results in faster and more efficient counting.

In Year 1 unitising is introduced in the summer term when working with the early stages of multiplication. Here, unitising is used to build familiarity with counters representing 1, 2, 5 and 10 (pre-money tokens) before handling real coins. Establishing concepts of unitising helps children avoid being confused by the relative size, shape and colour of coins rather than their value.

Unitising is a mathematical term used to describe counting groups of the same number of things as single units. It is vitally important when children expand their understanding of place value, where a one in the tens column represents ten and a one in the hundreds column actually represents one hundred.

We have not covered this idea before, but now have some interesting pages on unitising, found in our Maths mastery resources.