Second graders practice compensation within 100 in this Grade 2 worksheet. Nine fill-in items walk students through rounding one addend up to a friendly ten, adding, and subtracting the extra amount. Matching links problems like 46 plus 19 to their compensation step, such as 46 plus 20 minus 1. The sheet targets the common Grade 2 error of forgetting to adjust back after rounding.
Style:
Mental Math Within 100
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 48 + 19 can become 48 + 20, then subtract 1.
2. 48 + 20 = 68, then 68 - 1 = 67.
3. 35 + 29 becomes 35 + 30 - 1 = 64.
4. 44 + 39 becomes 44 + 40 - 1 = 83.
5. 27 + 18 becomes 27 + 20 - 2 = 45.
6. If you change 49 + 32 into 50 + 32 - 1, fill in the blank.
7. Using compensation, 25 + 48 = 25 + 50 - 2 = 73.
8. To add 63 + 19 use 63 + 20 - 1 = 82.
9. Compensation means you change one number to make it easier to add.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
46 + 19
→ 46 + 20 - 1
46 + 20 - 1
27 + 29
→ 27 + 30 - 1
27 + 30 - 1
52 + 38
→ 52 + 40 - 2
52 + 40 - 2
35 + 48
→ 35 + 50 - 2
35 + 50 - 2
Mental Math Within 100
★ Part A: Fill in the Blank
Write the missing word or number on each line.
1) 48 + 19 can become 48 + 20, then subtract 1.
2) 48 + 20 = 68, then 68 - 1 = 67.
3) 35 + 29 becomes 35 + 30 - 1 = 64.
4) 44 + 39 becomes 44 + 40 - 1 = 83.
5) 27 + 18 becomes 27 + 20 - 2 = 45.
6) If you change 49 + 32 into 50 + 32 - 1, fill in the blank.
7) Using compensation, 25 + 48 = 25 + 50 - 2 = 73.
8) To add 63 + 19 use 63 + 20 - 1 = 82.
9) Compensation means you change one number to make it easier to add.
★ Part B: Matching
Match each item on the left to the correct answer on the right.
1) Match each item to its correct answer.
46 + 19
→ 46 + 20 - 1
46 + 20 - 1
27 + 29
→ 27 + 30 - 1
27 + 30 - 1
52 + 38
→ 52 + 40 - 2
52 + 40 - 2
35 + 48
→ 35 + 50 - 2
35 + 50 - 2
Ready to Practice?
Complete each section carefully.
10 Questions
10-15 minutes
Auto-graded
Retry anytime
🏆
Questions Correct
0
Correct
0
Incorrect
0
Skipped
0:00
Time
0%
Score
Review Your Answers
See what you got right, missed, or skipped.