Alongside addition (which we’ve written about separately), subtraction is one of the first operations children will learn in maths. As with addition, there are more than a few methods floating about on how to teach subtraction, which can seem dizzying as a parent. And once again, there are some simple activities that you can work through with your child to introduce subtraction to their world.
Teach kids subtraction with songs and stories
Let’s start with the basics. One way to explain subtraction is that it is the opposite of addition. Children learn to add by counting forwards. To subtract, they now just need to count backwards.
Stories and songs are always a great way of making ideas stick. Maths can be found in many of your favourite ones. Here’s a cute example of counting backwards we’re particularly fond of:
♫ There were ten in the bed and the little one said: “Roll over! Roll over…” ♫
Subtraction songs like these illustrate that when something is removed (‘taken away’ or ‘subtracted’) there is less left behind.
To help your child understand that subtraction is the opposite of addition, use number bonds. For example, your child no doubt knows the number bond 2 + 3 = 5. But let’s now write this out in terms of subtraction:
5 – 2 = 3
5 – 3 = 2
How to explain subtraction with cookies
It often proves more tricky to teach kids subtraction compared to addition. One reason is that there are so many different ways to visualise and show subtraction methods. But this also gives you an opportunity to bring maths to life in your everyday routines. Why not make a list together of household activities that involve subtraction?
Whether you do subtraction with pictures, objects or symbols, the most important idea for your child to grasp is that subtraction gives you the difference between two quantities. For example, if I had 7 cookies and my greedy friend takes 3 cookies, how many cookies do I have left?
As you go through this exercise, your child may (excitedly) remove one cookie at a time until they have four in front of them. You can get them to visualise the process on a number line, starting at 7 and counting back one at a time up to three steps.
Notice how we are linking a concrete representation (cookies) with one involving number lines and symbols. These connections are important; they help your child to see the same operation, subtraction, in different ways. This will help them use subtraction flexibly from one situation to the next.
Your child (who may be the greedy friend in question!) will see there were 7 cookies to begin with, and that there are 4 left. So what you’ve actually shown is that the difference between 7 cookies and 4 cookies is 3 cookies (the amount you ‘took away’).
Get ready for large calculations with pictures
As your child progresses through the curriculum, they’ll be ready to take on larger numbers. It can be useful to have different objects to represent 1,10 and 100. For example:
Your child can visualise subtraction using these new symbols. Here is one way of representing 69 – 24:
Your child will gradually move onto more complex subtraction calculations and problems. The methods they encounter in school will sometimes be more formal than the ones we have shown here. And that’s perfectly fine – by visualising methods early on, your child will have a strong grasp of how subtraction works.
With that foundation, they’ll be ready for whatever sums (or subtractions) follow!