What Is Subitising And Why Is It Important? Tips For Parents & Teachers

Subitising is an essential part of developing number sense in young children. In this post, we explain what subitising means, how it might look in the classroom or at home and why it is important for developing maths skills.

What is subitising?

Subitising is the ability to look at a small set of objects and instantly know how many there are without counting them. For example, when rolling a dice we don’t need to count the dots to know what we have rolled. Subitising was first coined by theorist Piaget. It is important in the early development of number sense.

There are two types of subitising:

• Perceptual subitising
• Conceptual subitising

Perceptual subitising

Perceptual subitising is instinctive: we are able to look at the objects and just know what the number is without any further thinking. Children and adults alike are generally able to perceptually subitise smaller numbers up to 5.

Conceptual subitising

Conceptual subitising is the ability to look at a number of objects as a combination of smaller amounts. Looking at the dice example again, when we roll a 6 we do not instinctively know it is 6. Instead, we see two groups of 3, meaning there must be 6. 

Numbers can be grouped in different ways. For example, the number 8 can be interpreted by combining numbers like 3 + 5 or 4 + 4. Developing conceptual subitising skills is therefore an important step towards many other areas of maths. 

When do children learn about subitising in the national curriculum? 

Subitising is introduced and explored during the Early Years Foundation Stage (EYFS). Young children in nursery and reception are taught to subitise up to 5. 

Building upon this, they develop a deep understanding of numbers to 10, including understanding their composition using conceptual subitising. This also helps to develop number bonds to 5 and 10 during this stage of young learner’s education. 

How does subitising relate to other areas of maths?

Subitising is an important skill to develop in early years maths as it is a core stepping stone to other areas of numeracy. 

By encouraging young children to deepen their number sense, they gain a stronger understanding of how a number is made. This turns an abstract concept into something more meaningful. 

For example, 7 is not simply 7. 7 is in fact 1 + 6, 2 + 5, 3 + 4, and so on. It can even be broken down further, for example 1 + 2 + 4. 

Why is it important for children to learn about subitising?

By understanding how a number is made, children can then learn basic number bonds up to 10, meaning the pairs of numbers that add together to make 10, for example. 1 + 9, 2 + 8, 3 + 7, and so on. 

This understanding also acts as a springboard to other concepts such as part-whole, which will help children when they learn part-whole models and bar models in Key Stage 1 and 2.

Subitising is intrinsically linked to addition and subtraction. By first looking at addition, conceptual subitising demonstrates to children that addition can happen in any order and that it is commutative. 

For example, 4 + 5 = 9 and 5 + 4 = 9. 

Once they are more fluent in addition facts, children can recognise the inverse relationship with subtraction. Both of these skills require fluency in conceptual subitising, which in itself requires strong perceptual subitising ability.

These simple addition and subtraction facts support children through key stage 1 but also in key stage 2 where formal written methods are introduced. 

Column addition and column subtraction methods both require strong number knowledge. This way, children’s working memory is not taken up by simple arithmetic. Instead it can be used for exchanging within the calculation and applying other reasoning and problem solving skills.

If you have pupils struggling with subtraction, read our blog on subtraction in Year 5. You can also check out our range of free, downloadable addition and subtraction worksheets.

How to teach subitising

Here are some ideas for exploring subitising in your EYFS classroom, or even at home. Using concrete resources is key, as it enables children to physically explore the numbers before absorbing the abstract knowledge into their long term memory.

Groups of objects

• Asking children to identify how many objects they can see without counting is one of the simplest ways to introduce subitising.
• Objects could range from counters to cubes, or even to toy mini-beasts and dinosaurs. 
• You could also incorporate it into your outdoor learning using groups of pebbles or making tallies out of sticks.
• After working on perceptual subitising up to 5, you could begin asking children if they can combine groups of objects, starting simple with 1 + 2.

Dominoes

• The dot patterns on dominoes are some of the most universally well-known examples of subitising that we are exposed to in our lifetimes.
• Playing dominoes in small groups can help children become more fluent in these number patterns and quicker in their subitising ability.
• Why not make it even more exciting for your EYFS class by playing with giant outdoor dominoes? 

Dot patterns

• Linked to dominoes but less uniform in their layout, dot patterns can further develop subitising skills.
• Children can be challenged to identify the number without counting and identify different dot patterns that show the same amount.
• Children can try finding the odd one out.

Hands 

• Looking at fingers on hands is one of the most straightforward ways to start subitising.
• Perceptual subitising can be practised with 5 fingers on one hand, while conceptual subitising can be introduced by using all 10 fingers. For example, 6 fingers is one finger more than 5 fingers. 

Flashcards

• EYFS children can be shown representations of numbers on subitising cards, whether it be dot patterns or pictures of objects.
• Showing them the flashcard and then hiding it or turning it over can ensure children are prevented from counting the items and must actually use instantaneous subitising. 

Subitising games

• There are a number of ways games can be played in small groups to build subitising skills.
• This may include playing simple board games that use a dice, such as snakes and ladders.
• Playing with two dice can deepen children’s understanding further.
• Other games include snap and matching pairs, where various pictorial representations of numbers can be used in conjunction with number figures.

Tens frames and Numicon

• Common classroom resources such as ten frames and Numicon can encourage children to combine groups of numbers and develop conceptual subitising.
• Ten frames in particular can help children to see pairs of numbers.
• These can be easily reproduced at home by drawing the outlines on pieces of card and cutting them out.

3 examples of subitising in maths

Children in the early years can work through to develop their number sense. Working in small groups can expose children to other children’s thought processes. 

Question 1. Dominoes

Ask: What numbers can you see? Can you see any other numbers inside the number?

Answers may range from 7 to 3 and 4. You can encourage children to think deeper by asking them to spot pairs of 2 within the number, for example. 

Question 2. Coloured number patterns

Ask: How many numbers can you see in this whole number?

Children may give different answers. For example, ‘I see 5 yellow, 2 green and 1 blue. There are 8 altogether’. Alternatively they may group them by position (2 + 2 + 4 = 8).

Question 3. Subitising to 10

Ask: How many numbers can you find in 10?

Using a 10 frame, you can ask children to show what numbers they can see. They may give different answers that begin to embed number bonds. You can challenge them to find as many numbers inside 10 as possible.