Number Friends
Find the missing part. 6 and what make 10?
Is the equals sign muddling you up? Start here.
A short lesson with a balance that tips, so you can see that the equals sign means “the same as” and not “the answer comes next”. About about 3 minutes.
Show me what equals means →
What does the equals sign mean again?
For grown-ups
- How long: 10 to 15 minutes is plenty. Short and frequent beats long and occasional — the early-numeracy trials with the largest effects ran eight weeks or less.
- When they get one wrong: the page shows the working. Read it together rather than moving straight on. Feedback that explains is worth several times more than feedback that only marks right or wrong, and that gap is wider in maths than in any other subject.
- Not timed: thinking time is the point of a book. Let silences run.
- Print it too: doing the same problems on paper a few days later is worth more than doing twice as many today.
What this practises
Number bonds to 10 — the two parts that make a whole, in both directions.
Part-whole reasoning, in the Singapore-style bond rather than as a sum, so the relationship is visible rather than procedural. Pairs to ten are the highest-leverage facts in early arithmetic: they underwrite every make-ten strategy that follows.
- The underlying idea
- Part-whole structure: a quantity is composed of parts, and the bond makes that visible.
- Where this sits in Illustrative Mathematics
- Kindergarten Unit 4: Understanding Addition and Subtraction · Kindergarten Unit 5: Composing and Decomposing Numbers to 10
- Sources
- Illustrative Mathematics / Kendall Hunt (2024) · What Works Clearinghouse (2023) · Clements (1999) all references →
Related measured skills: ARF · Addition facts, ALPACA · Early number. What this means