Tuck Breaks a Ten — Subtract with Regrouping (Grade 2)

About this activity

Tuck the hamster shows base-ten blocks while children subtract a one-digit number from a three-digit number when there are not enough ones — problems like 342 − 5 and 213 − 7 — tapping 'Break a ten' to turn one ten-rod into ten ones, then taking some away and typing the answer. It's a free, interactive Grade 2 math activity that runs right in the browser with no account.

The big idea is the first meaning of borrowing: when you do not have enough ones, you trade one ten for ten ones. Instead of crossing out and writing a little 1, the child watches a ten-rod break apart into ten unit-cubes, joining the ones already there so there are now plenty to take away. The blocks make the trade real before the written subtraction algorithm is introduced.

It is aligned to Common Core 2.NBT.B.7 — subtracting within 1000 using concrete models and understanding that you sometimes decompose a ten. No timer, no score — just calm, playful practice.

What's inside this activity

• Designed for Grade 2 learners (ages about 7–8)
• Common Core strand: Number & Operations in Base Ten
• Aligned to Common Core standard 2.NBT.B.7

How to play

Read the subtraction, like 342 − 5, and watch Tuck show the blocks.

Tap 'Break a ten' to turn one ten into ten ones, then take some away.

Type the answer on the keypad; try again any time, with no timer and no score.

What your child practices

• Subtract a one-digit number when there are not enough ones
• Break one ten-rod into ten unit-cubes
• Understand borrowing as decomposing a ten into ten ones
• Type the correct answer after regrouping

Learning goals

Subtract within 1000 with regrouping — the focus of Common Core 2.NBT.B.7

Understand that one ten decomposes into ten ones

Build the place-value meaning behind written subtraction with borrowing