Addition flash cards

Tick the numbers to add, from 1 to 12. Ticking 7 deals 7 + 1 up to 7 + 10, or 7 + 12. Turned round too adds 3 + 7 next to 7 + 3.

Press the card or Space to see the answer, then choose Knew it or Still learning. Missed cards come back three cards later until they're known, and the end of the deck lists them.

For subtraction, set Cards to Subtraction. Each card then undoes an addition fact, so ticking 7 gives 8 − 7 up to 17 − 7. None of the answers go below zero.

Print both sides, flipping on the long edge, at 100% size. The backs are mirrored left to right so each answer lands behind its sum. With a one-sided printer, choose Fold and fold each card down the middle.

By the end of grade 2, the US Common Core expects children to know from memory all sums of two one-digit numbers, and to add and subtract within 20 using mental strategies (2.OA.B.2). Ticking 1 to 9, up to 10, covers those sums apart from adding zero.

Doubles like 6 + 6 tend to stick first. Near doubles follow from them, since 6 + 7 is one more. The number bonds page draws the pairs that make 10.