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Grade 3 Math · World 2: Add-and-Subtract Express · Level 15
Break a Ten or a Hundred
Subtract with regrouping, including across zeros: 400 − 167.
Warm-up, learn, try it together, practice, then a quick check. About 15 minutes.
What children learn in Level 15
- Try 352 minus 127. There aren't enough ones to take away 7, so break a ten into 10 ones.
- Now there are 4 tens and 12 ones. 12 minus 7 is 5, 4 tens minus 2 tens is 2 tens, and 3 hundreds minus 1 hundred is 2 hundreds.
- Zeros need two breaks. For 400 minus 167, break a hundred into 10 tens, then break a ten into 10 ones.
- Now subtract: 10 minus 7 is 3, 9 tens minus 6 tens is 3 tens, and 3 hundreds minus 1 hundred is 2 hundreds. 400 minus 167 is 233!
Georgia's K-12 Mathematics Standards:
- 3.PAR.2.1 — Fluently add and subtract within 1000 to solve problems.