What's 8 + 6? A 6-year-old who doesn't know number bonds counts: 8, 9, 10, 11, 12, 13, 14. Slow, finger-counting. A 6-year-old who does know number bonds thinks: "8 + 2 = 10. 6 - 2 = 4. 10 + 4 = 14." Fast. The difference between slow and fast mental maths — and it's number bonds behind it.
This article shows how to teach number bonds to 10. At Kluriko number bonds are one of the most important exercises in the Learning Games' maths section — and they can be supported at home too.
What are number bonds?
Number bonds are pairs of numbers that together make 10.
- 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
They should say them automatically. At age 7. Like they can say their name.
Why are they so important?
Because mental maths over 10 builds on them.
Example: 7 + 5 = ?
With number bonds: "7 + 3 = 10. 5 - 3 = 2. 10 + 2 = 12."
Without: 7, 8, 9, 10, 11, 12. (Finger counting. Slow. Error-prone.)
True for all addition and subtraction over 10. Number bonds are the foundation.
How to teach them
Exercise 1: Fingers
Both hands = 10 fingers. They show 3 fingers. "How many are hidden?" 7. Number bond 3+7.
Do it for each pair: 1-9, 2-8, 3-7, 4-6, 5-5.
Exercise 2: Bead string
10 beads on a string. They slide 4 to one side. "How many on the other?" 6.
This is the most direct way to show number bonds. Buy a "rekenrek" or make one with a string and 10 beads.
Exercise 3: Count down from 10
"We have 10 apples. I take 3. How many left?" They count.
Exercise 4: Two-card game
Use a deck with cards 1-9 (remove 10 and picture cards). Split into two piles. Flip one card at a time — does the pair make ten? Say "number bond!". (Ace = 1.)
Exercise 5: Quick flash cards
"3 + ?" They say "7". "8 + ?" They say "2".
Flash cards work — but only if they already understand what number bonds are. Not chanting without understanding.
Song and chant
"One and nine, number bonds. Two and eight, number bonds. Three and seven, number bonds. Four and six, number bonds. Five and five, number bonds to ten!"
Sing. They learn melody + numbers.
When are they ready?
Age 5: can start seeing bonds to 5. (2 + 3, 1 + 4.)
Age 6: can start actively learning bonds to 10.
Age 7: should know bonds to 10 automatically.
Age 8: extends to bonds to 20 (12 + 8, 15 + 5, etc.).
Patterns in number bonds
They'll notice:
- 1+9, 2+8, 3+7, 4+6 — the first number is less than 5
- 5+5 — the only pair where both are the same
- 6+4, 7+3, 8+2, 9+1 — the first number is more than 5
They see symmetry in number bonds. Beautiful maths.
Common problems
They can chant but not use. "3+7=10, 4+6=10..." they chant. But "8 + ? = 10"? They don't know. They've memorised but not understood. Back to fingers and beads.
They mix bonds to 10 with addition in general. "What's 6+4?" "10!" "What's 6+5?" "10..." (unsure). Show the difference clearly.
They handle bonds to 10 but not over. Good starting point. Then extend to bonds to 20.
Bonds to 20
After 10 comes 20:
- 1 + 19 = 20
- 2 + 18 = 20
- ...
- 10 + 10 = 20
Less common to memorise, but useful for mental maths.
How bonds solve problems
8 + 6 = ?
Think: "8 is 2 from 10. 6 - 2 = 4. 10 + 4 = 14."
Called "make ten" — one of the central maths strategies in primary school.
13 - 7 = ?
Think: "13 is 3 from 10. 7 - 3 = 4. 10 - 4 = 6."
This is "borrow from ten" — the other central strategy.
Both build on number bonds. Both become fast once bonds sit.
Teacher confirmation
If they manage bonds to 10 at age 7 — tell the teacher. It's a clear sign of good maths development.
Number bonds are the core
Of all the maths they learn in primary, bonds to 10 are the most decisive building block. Not times tables. Not long addition. Bonds.
Invest time there. The rest gets easier.
How Kluriko helps
Kluriko Learning Games have number-bond games where they see a number and pick the partner. Repeated pattern training that builds automation. Ten minutes a day, two weeks — they know the pairs.