Have you heard of the term one-to-one correspondence before? You’ll probably know what it is as soon as I explain it, but you might not have heard of the term before. One-to-one correspondence is one of the most important maths skills in the early years of learning mathematics. Once your child has mastered this skill, they will be able to confidently grasp other numeracy concepts too.
You might be thinking that counting by rote up to 10, 50 or even 100 is an impressive skill for a child in the early years. Whilst on the surface it is, reciting numbers doesn’t mean that the child has any concept of what those numbers mean in a tangible sense – sorry to burst your bubble!
So what is one-to-one correspondence?
One of my friends once asked me, ‘How do you actually teach kids to count to 10?’ Like many who aren’t educators, she initially thought teaching young children would be a breeze. But when she stopped to consider it, she realised it’s not as straightforward as it seems. When you’ve been doing something like counting your entire life, you don’t think about the underlying skills involved until you’re in the position of teaching them to someone else.
To put it in simple terms, let’s say a child is doing an activity based on the book ‘Dear Zoo’. They have a set of toy animals and a set of small boxes to put them in. If you ask the child to place one animal in each box, and they can do this successfully, they understand one-to-one correspondence. If the child, however, puts multiple animals in one box, or distributes animals randomly across boxes, it’s a sign they haven’t grasped the concept yet.
In a nutshell, one-to-one correspondence is about understanding what each number represents.
Why is it important to teach one-to-one correspondence?
One-to-one correspondence is a key early math skill that your child needs to grasp, often before you even think about diving into addition and subtraction. Think of it as teaching your child to count their building blocks by pointing at or picking up each block and saying a number for every single one. Some kids like to transfer the blocks from one bucket to another as they count, making sure each block is accounted for. This practice helps them answer the question, ‘How many blocks are there?’
Understanding one-to-one correspondence is a stepping stone to grasping the real value of numbers. Your child will learn that each item being counted is associated with a unique number and that you can only count each item once. The last number they say in the counting sequence will tell them the total number of items they’ve counted. So whether your child is counting crayons, toy cars, or even the number of apples in a fruit bowl, remember, there are some essential rules of counting that they’ll learn along the way, and we’ll delve into those as we go on.
I first learnt the term one-to-one correspondence whilst undergoing my teacher training. This concept, along with subitising and rote counting, plays a part in helping children to become more confident mathematicians. One reason I am so passionate about making the early years of mathematics playful and hands-on is because I found maths difficult as a child.
If you take the time to create activities based around one-to-one correspondence in the early years, it is more likely that your child will grasp more complex mathematical concepts as they grow older.
The TV show Numberblocks is perfect for learning one-to-one correspondence in a fun, no-prep way. There is also a range of multi-link cubes available via Learning Resources that I recommend for helping children to grasp the concept further.
One-to-one correspondence versus counting by rote
Many parents understandably confuse rote counting with the concept of one-to-one correspondence, but they are actually quite different, even though both involve numbers. Rote counting is more like reciting the alphabet—it’s saying the sequence of numbers (‘1, 2, 3, 4, 5’) in the right order, but without linking those numbers to actual objects. Your child might be great at saying numbers in order while jumping on the trampoline, but that doesn’t mean they’re counting anything specific.
On the other hand, one-to-one correspondence is about counting real things—like toy dinosaurs, marbles, or even fingers—and saying the correct number for each item. For instance, as your child puts one marble into each hole of a muffin tin, they would say ‘one’ for the first marble, ‘two’ for the second, and so on. This practice not only helps your child to connect numbers to actual objects, but also teaches them that these numbers represent value. The last number tells them how many marbles are in the muffin tin altogether
In this section, you’ll find photograph inspiration of activities involving one-to-one correspondence. I recommend that you recreate variations of this activity with your preschooler on a regular basis so that they grasp the concepts.
Start slow. Try 1-3 first, then 1-5 and so on.
Dot Sticker Match
The Very Hungry Caterpillar Counting Activity
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