Subtraction Facts to 20: A Whole Page of Take-Away

Twelve subtraction facts within 20 are laid out in a grid on this Grade 1 page, each with an answer box beside it. No additions appear anywhere, and there is no room for written working — the child reads a fact such as 15 minus 8, works it out mentally, and writes the difference. Both the number taken away and the answer are always at least two, so no card is solved for free.

Subtraction lags behind addition for most first graders, and a page devoted to it is the fastest way to find out why. There are two good routes to 15 minus 8 — counting back eight, or counting up from 8 to 15 — and they are not equally efficient. Children who only ever count back struggle badly once the gap grows, and they lose their place around ten. Watching which route a child takes on the harder facts tells you far more than the number of ticks does, and it points straight at the strategy that needs teaching next.

Print the PDF free and ask a child to explain one answer out loud, because that is where the strategy shows itself. Addition facts to 20 makes the natural companion sheet, and children who need the ideas underneath can spend a page on number bonds within 10 before coming back.