What is subitising and why is it important?

When you are playing a game with a dice and you roll a six, do you count the dots before realising it’s a six?  I’m sure the answer is a resounding NO because you have grown up using a dice and so you can instantly recognise the numbers from the arrangement of the dots.

The ability to recognise numbers of things without counting them is called subitising and it develops from a very early age.  Young children have powerful visual memories and some find it easier to remember images than words. Subitising can help children to build visual images for numbers, which in turn helps them to learn number facts.

Why is it important?

Subitising is an essential skill when it comes to adding and subtracting larger groups of numbers.  Recognising a larger group by combining smaller groups numbers (known as conceptual subitising) helps children to manipulate numbers to make calculations easier.

For example, when calculating 8+5, it is easier if you know that 5 can be broken into a 2 and a 3 so that you can add the 2 first to make 10, and then the 3 to make 13.

What can I do to help?

Exposing children to visual representations of numbers from an early age will help to develop their ability to subitise.  Simply learning how to count on a number line is not enough as children need to use practical equipment to ‘build’ and then draw these numbers to understand their value.  Playing board games with a dice is a great start and one that is all too often forgotten in today’s technology-dependent world.  Having a set of digit cards from 1 to 10 and getting children to build these numbers using counters, toys, sweets, coins or anything you can find will all help them to develop a better understanding of the value of numbers.

Number Stacks is a great tool for developing subitising. Visual representations of single digit numbers is one of the very first skills covered in our Number Stack video tutorials.

NPV1: Read & Write numbers to 10

To practise conceptual subitising, encourage children to look for smaller groups of objects within a larger group and see if they can put these together.  To help with this, I have created a simple card game with different representations of numbers up to 10.  Initially, children may have to count the number of red ‘ones’ on each card but with repeated practice, they should begin to instantly recognise the larger of the two groups on the card and count on the extra, before eventually recognising the two groups and adding them with no counting.

When I have played this game with children, we work through the cards, timing how long it takes to correctly identify the number shown on every card in the set.  Children are very keen to beat their time and eventually become very fast!

Download our Subitising Card Game Here

You can download the whole set of cards using the link above.  I have laminated my set (what teacher doesn’t love a laminator!) but you can just as easily print them on paper and stick them on card to make them last.

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