10 printable sets · answer key on every set
Subtraction Within 100 Worksheets
What this skill is
Two-digit subtraction that requires regrouping — 52 − 27.
When it comes up: Middle of second grade. This is the skill most second graders struggle with longest.
The mistake to watch for
Subtracting the smaller digit from the larger in each column regardless of which is on top: 52 − 27 answered as 35, from 7 − 2 and 5 − 2.
How to help
Before solving, have your child circle any column where the top digit is smaller. Naming the regroup before doing it prevents the reflex.
Next: Three-digit addition and subtraction.
A worked example
Try 52 − 27. You cannot take 7 ones from 2 ones, so regroup: 52 is 4 tens and 12 ones. Now 12 − 7 = 5 ones and 4 tens − 2 tens = 2 tens. The answer is 25.
Words to know
- subtract
- To take one number away from another to find how many are left.
- regroup
- To trade 10 ones for 1 ten (or 1 ten for 10 ones) when you add or subtract.
- difference
- The answer you get when you subtract.
- ten
- The number 10, one more than nine.
- digit
- One of the ten number symbols 0 to 9. The number 47 has two digits.
Practice
Subtract. Regroup when you need to.
Showing Set 1 · 20 problems
- 87 − 9 =
- 35 − 8 =
- 81 − 57 =
- 82 − 59 =
- 73 − 15 =
- 72 − 39 =
- 86 − 29 =
- 75 − 16 =
- 40 − 15 =
- 35 − 16 =
- 51 − 24 =
- 71 − 27 =
- 34 − 8 =
- 10 − 5 =
- 43 − 36 =
- 50 − 7 =
- 45 − 38 =
- 47 − 39 =
- 48 − 29 =
- 76 − 18 =
Download this set20 problems · answer key included PDF
Answer key
- 78
- 27
- 24
- 23
- 58
- 33
- 57
- 59
- 25
- 19
- 27
- 44
- 26
- 5
- 7
- 43
- 7
- 8
- 19
- 58
All 10 sets
Each set is a different list of 20 problems with its own answer key. Use the buttons above to look at one on this page, or download any of them as a PDF.
- Set 120 problems · answer key includedPDF
- Set 220 problems · answer key includedPDF
- Set 320 problems · answer key includedPDF
- Set 420 problems · answer key includedPDF
- Set 520 problems · answer key includedPDF
- Set 620 problems · answer key includedPDF
- Set 720 problems · answer key includedPDF
- Set 820 problems · answer key includedPDF
- Set 920 problems · answer key includedPDF
- Set 1020 problems · answer key includedPDF
- Problems are generated for each set and checked against 2.NBT.B.5 before the sheet is built — no duplicates, and every problem falls inside the standard's number range.
Common Core State Standards © 2010 National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.