Addition fact family worksheets
Six triangles, each hiding four facts — addition and subtraction taught as one relationship.
Best fit: 1st–2nd grade · Answer key included · Free, no sign-up
Answer key
The same sheet with every answer shown in blue — print it for marking, or hand it over for self-checking.
About these worksheets
The addition version of the fact-family triangle: the whole on top, two parts below, and four facts to write — two sums, two differences. This is subtraction taught the friendly way: 15 − 8 isn’t a new operation, it’s “8 and what make 15?”. Children who think in fact families barely notice subtraction as a separate thing to learn.
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Frequently asked questions
What are the four facts in an addition family?
For 7, 8 and 15: 7+8=15, 8+7=15, 15−7=8 and 15−8=7. One triangle, four facts.
How does this help with subtraction?
It reframes subtraction as a missing-part question, which is how fluent adults actually compute it — no counting backwards required.
What grade are these for?
1st and 2nd grade, alongside addition facts within 20.