Number bonds to 10 and 20 · Grade R
In Grade R you learn: number bonds to 5.
Number bonds are pairs of numbers that make a total, like 7 and 3 make 10. Knowing the bonds to 10 and 20 by heart makes adding, subtracting and giving change much quicker, because you can always see how far it is to the next 10.
Key facts
- Bonds to 10: 0 + 10, 1 + 9, 2 + 8, 3 + 7, 4 + 6, 5 + 5.
- Every bond gives four facts: 7 + 3 = 10, 3 + 7 = 10, 10 − 3 = 7, 10 − 7 = 3.
Worked examples
Example 1
A ten frame has 6 dots. How many more dots fill it?
Answer: 4