Addition with Regrouping
Free regrouping game: 3-digit column addition with carrying, like 356 + 187, solved digit by digit. For grades 2–3. Plays in your browser.
Grade 2–3 · Free · No sign-up
How to play & why it works
Every round is a three-digit column sum that needs at least one carry — 356 + 187 — answered digit by digit from the ones. Regrouping is guaranteed, so the skill under practice is always the carry itself, not just column addition.
Carrying is the first genuinely multi-step procedure children meet, and the classic failure mode is losing track mid-problem: carry the one, then forget it existed. Repetition in a fast, low-stakes format is what turns the carry from a conscious step into a reflex.
Narrate the carry while you play: "6 plus 7 is 13 — write 3, carry 1." Saying the carry out loud is the single most effective fix for dropped-carry errors, and the game gives you eight chances a round to make it stick.
The free MathIt app extends regrouping to four-digit sums and missing-number variants, and its adaptive engine notices exactly which carry patterns trip you up.
Every problem here carries at least once, which is the point: regrouping practice that only sometimes requires regrouping lets a child pass by luck. The carried digit is where errors cluster — it is written small, above the next column, and it is the thing most often forgotten under time pressure.
What a carry actually means is worth saying plainly: ten ones have been exchanged for one ten. Children who treat it as a rule about small numbers written above the line tend to lose it when the numbers get longer; children who understand the exchange do not.
Skills you'll practice
Keep practicing
Frequently asked questions
What is regrouping in addition?
When a column adds to 10 or more, you keep the ones digit and carry the tens digit into the next column. It is the same idea as trading ten pennies for a dime.
What grade is addition with regrouping?
Second grade for two-digit numbers and third grade for three-digit, in most curricula. It comes straight after plain column addition.
Why does my child forget to add the carried number?
Because it is written outside the sum and easy to overlook once attention moves to the next column. Saying the carry aloud as it is written — 'carry the one' — is a small habit that fixes most of these errors.
Get the full game
Adaptive difficulty, daily streaks, and live 2–5 player math battles — free on iOS and Android.