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addition

Number bonds for addition

Use known pairs to build flexible addition facts.

Quick answer

Number bonds for addition are pairs of numbers that add up to a given total. You can use these to help you add numbers quickly and easily.

Learning outcome

By the end of this page, you will be able to find number bonds for any given number and use them to solve addition problems. Success signs:
  • You can name pairs of numbers that add up to 10, 20, or any other number.
  • You can use number bonds to solve addition problems quickly.
  • You can explain how number bonds help you add numbers in your head.
  • You can make your own number bonds for different totals.

Why this matters

Number bonds help you understand how numbers work together. They make addition easier because you already know some pairs of numbers that make a certain total. When you know your number bonds, you can add numbers faster and more confidently. This skill helps in school maths, cooking, shopping, and even in games where you need to count points or score.

How it works

Number bonds are pairs of numbers that add up to a specific total. For example, the number bonds for 5 are:
  • 0 + 5 = 5
  • 1 + 4 = 5
  • 2 + 3 = 5
  • 3 + 2 = 5
  • 4 + 1 = 5
  • 5 + 0 = 5
You can use these pairs to help with addition problems. If you know that 2 + 3 = 5, then you also know that 3 + 2 = 5. This is because addition is commutative – the order of numbers doesn’t change the total.

Examples you can see

Let’s look at some examples with number bonds for different totals. Number bonds for 10:
First number Second number Total
0 10 10
1 9 10
2 8 10
3 7 10
4 6 10
5 5 10
6 4 10
7 3 10
8 2 10
9 1 10
10 0 10
Number bonds for 20:
First number Second number Total
0 20 20
1 19 20
2 18 20
3 17 20
4 16 20
5 15 20
6 14 20
7 13 20
8 12 20
9 11 20
10 10 20
These tables show all the possible number bonds for 10 and 20. Notice how the pairs go up and down – 1 and 9, 2 and 8, 3 and 7, and so on.

Try it as a mini adventure

Adventure: The Number Bond Hunt You are on a treasure hunt! To find the treasure, you must solve addition problems using number bonds. Here are the clues: 1st time: You find 3 apples and 7 oranges. How many fruits are there in total? 2nd time: You have 6 stickers and 4 more stickers. How many stickers do you have? 3rd time: You collect 8 shells and 2 more shells. How many shells do you have? 4th time: You have 5 candies and 5 more candies. How many candies do you have? 5th time: You find 9 marbles and 1 more marble. How many marbles do you have? Now, try to solve each clue using number bonds. For example, for clue 1, you know that 3 + 7 = 10 because 3 and 7 are number bonds for 10.

Common mistakes

  • Mistake: Thinking that 4 + 6 = 10 and 6 + 4 = 11.
    Why it happens: Confusing the order of numbers in addition.
    Fix: Remember that addition is commutative – 4 + 6 = 6 + 4 = 10.
  • Mistake: Forgetting that 0 + 5 = 5.
    Why it happens: Not thinking about zero as a number.
    Fix: Remember that adding zero to any number gives the same number.
  • Mistake: Counting on fingers for every problem.
    Why it happens: Not knowing number bonds well enough.
    Fix: Practice number bonds regularly until you know them by heart.

Parent and carer guide

As a parent or carer, you can help your child learn number bonds in a few simple ways:
  • Play games where you ask your child to find number bonds for different totals.
  • Use everyday objects like counters, toys, or fruits to make number bonds visible.
  • Encourage your child to say number bonds out loud to build memory.
  • Use number bond flashcards for quick practice during quiet times.
  • Make it fun by turning number bonds into a race or challenge.
Remember, it's okay if your child doesn't get it right away. Practice makes progress, and number bonds are a foundation for more complex maths.

Practice questions

  1. What are the number bonds for 8?
  2. What is 3 + 7?
  3. What is 9 + 1?
  4. What is 6 + 4?
  5. What is 2 + 8?
Answers:
  1. 0 + 8, 1 + 7, 2 + 6, 3 + 5, 4 + 4, 5 + 3, 6 + 2, 7 + 1, 8 + 0
  2. 10
  3. 10
  4. 10
  5. 10

FAQ

What are number bonds?

Number bonds are pairs of numbers that add up to a given total. For example, 3 and 7 are number bonds for 10 because 3 + 7 = 10.

Why do we learn number bonds?

Number bonds help you understand how numbers work together. They make addition easier and faster because you already know some pairs that make a certain number.

How many number bonds are there for 10?

There are 11 number bonds for 10: 0 + 10, 1 + 9, 2 + 8, 3 + 7, 4 + 6, 5 + 5, 6 + 4, 7 + 3, 8 + 2, 9 + 1, 10 + 0.

Can I use number bonds for bigger numbers?

Yes! You can use number bonds for any number. For example, the number bonds for 20 include 12 + 8, 15 + 5, 10 + 10, and so on.

How can I practice number bonds?

You can practice by using flashcards, playing games, or solving addition problems using known number bonds. Try to find number bonds for numbers you see in your everyday life.