Number bonds to 10
The pairs that make ten.
A number bond is the part-part-whole picture of a number: seven is three and four, and also two and five. Knowing the bonds to ten by heart (typically ages five to seven) is the single strongest predictor of fluent mental addition and subtraction later.
Play this lesson with narration →A pile of ten
Ten Yazies split into two groups.
We have ten Yazies. If we split them into two groups, how many ways can we do it? Let's find out.
The number bond
A whole and two parts.
A number bond is three circles. The big one is the whole — that's ten. The two little ones are the parts. Six and four make ten.
All the bonds to 10
Every pair that makes ten: one and nine, two and eight, three and seven, four and six, five and five. These are the number bonds to ten — the most important pairs in math.
Write the family
Every bond gives us four equations. Six plus four equals ten. Four plus six equals ten. Ten minus four equals six. Ten minus six equals four. That's a fact family.
Missing part
The whole is ten. One part is seven. What's the other part?
What parents should watch for
- Treating 3 + 4 = 7 and 4 + 3 = 7 as two unrelated facts.
- Not seeing that the same bond gives the subtraction facts 7 − 3 and 7 − 4.
- Finding one decomposition of a number and assuming it is the only one.
- Reading the bond diagram as a sum to compute rather than a relationship to hold.
Land 32 · Number Bond Bay — 13 levels for ages 4–7 in the number sense strand.
Play Number Bond Bay in the Yaze Adventure Map — games built on this exact skill.
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