Learning subtraction — subtracting with strategy

In subtraction, a subtrahend is taken from the minuend; the result is called the difference. The most important mental strategies: stepping backwards over ten (13 − 5 becomes 13 − 3 − 2), adjusting to neighbor tasks (13 − 5 = 13 − 6 + 1) and thinking in inverse operations — whoever knows 7 + 6 = 13 automatically knows 13 − 6. Grades 3–4 add splitting into tens, written subtraction and completing missing numbers like __ − 8 = 7. Halving tasks (16 − 8) are the bridge to the times tables.