Fast Addition: Split, Round and Compensate

Mental addition gets easier when you transform awkward numbers into friendly ones.

Split by place value

347 + 126 → 347 + 100 + 20 + 6 = 473. Keep the running total simple.

Round and compensate

398 + 247 → 400 + 247 − 2 = 645. Moving to a round number reduces mental load.

Make tens first

58 + 27 → 58 + 2 + 25 = 85. Take what you need from the second number to complete the next ten.

Practice in short sets

Do 5–10 calculations with one technique. Accuracy first; only shorten the time after the method feels automatic.

Educational note: these techniques are practice methods, not medical or cognitive-performance claims.