Addition with regrouping (often called carrying) is one of the big ideas of second grade. Students learn to add within 100 fluently using place value (Common Core 2.NBT.B.5) and then extend the same method to numbers within 1,000 (2.NBT.B.7). The key moment comes when the ones add up to 10 or more: ten ones are traded for one ten, and that ten is added into the tens column. The same trade happens when ten tens become one hundred.
These questions start with two-digit sums and build to three-digit sums, word problems, a missing addend and a quick estimate. Encourage your child or class to line up the digits by place value, add the ones first, and say the trade out loud: "13 ones is 1 ten and 3 ones." Each question can be checked instantly, and every answer has a worked explanation so students can see exactly where a slip happened. A quick estimate before adding is a great habit for catching answers that are far too big or too small.
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Answer: B) 85
Add the ones: 7 + 8 = 15. That is 1 ten and 5 ones, so write 5 and carry 1 ten. Add the tens: 4 + 3 + 1 = 8 tens. The answer is 85.
Answer: 83
Ones: 6 + 7 = 13, so write 3 and carry 1 ten. Tens: 5 + 2 + 1 = 8. The answer is 83.
Answer: C) 58 + 26
Look at the ones in each problem. 4 + 5 = 9, 1 + 7 = 8 and 2 + 5 = 7 are all less than 10. Only 8 + 6 = 14 makes 10 or more, so 58 + 26 needs regrouping.
Answer: 613
Ones: 5 + 8 = 13, write 3 and carry 1 ten. Tens: 6 + 4 + 1 = 11, write 1 and carry 1 hundred. Hundreds: 3 + 2 + 1 = 6. The answer is 613.
Answer: B) 83
Add 38 + 45. Ones: 8 + 5 = 13, write 3 and carry 1 ten. Tens: 3 + 4 + 1 = 8. Maya has 83 stickers.
Answer: 62
Add the ones: 9 + 9 + 4 = 22, so write 2 and carry 2 tens. Add the tens: 1 + 1 + 2 + 2 = 6. The answer is 62.
Answer: B) Write 3 in the ones place and add 1 ten to the tens column
13 ones is the same as 1 ten and 3 ones. The 3 stays in the ones place and the 1 ten is added into the tens column.
Answer: 634
Ones: 8 + 6 = 14, write 4 and carry 1 ten. Tens: 7 + 5 + 1 = 13, write 3 and carry 1 hundred. Hundreds: 4 + 1 + 1 = 6. The answer is 634.
Answer: C) 404
Ones: 9 + 5 = 14, write 4 and carry 1 ten. Tens: 0 + 9 + 1 = 10, write 0 and carry 1 hundred. Hundreds: 2 + 1 + 1 = 4. The answer is 404.
Answer: 233 (also accepted: 233 books)
Add 146 + 87. Ones: 6 + 7 = 13, write 3 and carry 1. Tens: 4 + 8 + 1 = 13, write 3 and carry 1 hundred. Hundreds: 1 + 1 = 2. There are 233 books.
Answer: A) 36
Think: what do I add to 36 to make 72? Check 36 + 36: ones 6 + 6 = 12, write 2 and carry 1; tens 3 + 3 + 1 = 7. That makes 72, so the missing number is 36.
Answer: 99
Ones: 4 + 8 + 7 = 19, write 9 and carry 1 ten. Tens: 6 + 2 + 1 = 9. The answer is 99.
Answer: B) 80
49 rounds to 50 and 32 rounds to 30. 50 + 30 = 80. The exact answer, 81, is very close to the estimate.
Students regroup 13 ones into 1 ten and 3 ones, then forget to add the 1 into the tens column, so 47 + 38 comes out as 75 instead of 85.
Writing 15 in the ones place gives answers like 715. Only one digit can sit in each place; the extra ten moves to the tens column.
When adding 365 + 48, the 4 must sit under the 6 (tens), not under the 3. Line numbers up from the ones place on the right.
If the ones add up to 9 or less there is nothing to trade. Check the ones total before carrying.
Turn addition with regrouping into a printable, differentiated worksheet with an answer key, matched to grade 2.
Make a worksheet βBuild a test or quiz on this topic that students answer online and that marks itself, with a class summary for you.
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Open the student portal βIt is adding when a column adds up to 10 or more. You trade 10 ones for 1 ten (or 10 tens for 1 hundred) and add it into the next column to the left.
Yes. Carrying is the older name. Regrouping describes what is really happening: a group of ten is moved to the next place value.