Number bonds to 20
Worksheet + game · PDF · free
Bonds to 20 extend bonds to 10. If 6 + 4 = 10, then 16 + 4 = 20 and 6 + 14 = 20. Teach children to find the bond to ten first, then adjust. A ten frame with two rows makes twenty visible. Pairs like 12 + 8, 13 + 7, and 15 + 5 should become as fluent as bonds to ten. These facts support subtraction across twenty — 20 − 14 — and mental strategies before written column methods. Practise missing addends: 20 = □ + 11, not only □ + □ = 20.
Worked example
For 14 + □ = 20, think what 14 needs to reach 20. From 14 to 20 is 6, so 14 + 6 = 20. Check: 6 + 14 = 20 too.
Watch for this
Reverting to counting on one by one from 14 — fifteen, sixteen, seventeen — is slow and breaks with larger numbers. Prompt: 'What goes with 4 to make 10?' then use 14.
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Same facts, played
A short game that drills the same idea after the page is printed.