Number Bonds to 10 and 20.

What is a number bond?

This is very simply a combination of numbers which fit together. 

Children must know the number bonds that make 10.
10 can be made up out of:

• 1 and 9
• 2 and 8
• 3 and 7
• 4 and 6
• 5 and 5 

If your child has instant recall of each of these number bonds and all of the ways they can fit together, they’ll be well on the way to dealing with arithmetic confidently and quickly. Ideally, they’ll also know their number bonds to 4, 5, 6, 7, 8 and 9.

Children must also know the number bonds that make 20. 

20 can be made up out of 

• 1 and 19
• 2 and 18
• 3 and 17
• 4 and 16
• 5 and 15
• 6 and 14
• 7 and 13
• 8 and 12
• 9 and 11 
• 10 and 10

Knowing your number bonds fluently up to ten is one of the foundations to more complex arithmetic such as adding and subtracting with the ‘column methods’ and mental addition and subtraction to 100 and beyond.