This Grade 2 mental math worksheet challenges second graders to add two two-digit numbers mentally within 100. Four multiple choice items ask students to choose the best strategy, such as compensation or break-apart, for problems like 34 plus 29 and 58 plus 19. Five fill-ins apply these same strategies to finish the computation, building Grade 2 flexibility so students pick the right approach for each addition problem they see.
Style:
Mental Math Within 100
Part A: Multiple Choice
Circle the best answer for each question.
1. Which strategy works best for 34 + 29?
A) 34 + 30 - 1
B) 34 + 30 + 1
C) 34 - 30 + 1
D) 34 + 20 + 9 + 1
2. Which is the best break-apart step for 46 + 27?
A) 40 + 20 and 6 + 7
B) 46 + 20 + 7
C) 40 + 6 only
D) 46 - 27 and add back
3. Which approach is easiest for 58 + 19?
A) 58 + 20 - 1
B) 58 + 10 + 9
C) 58 + 19 on paper
D) 58 - 20 + 1
4. Which strategy is best for 25 + 38?
A) 25 + 40 - 2
B) 25 + 38 by ones
C) 25 + 30 + 10
D) 25 - 38 + 2
Part B: Fill in the Blank
Write the correct answer on each line.
1. 34 + 29 using compensation is 34 + 30 - 1 = 63.
2. 46 + 27 by break-apart: 40 + 20 = 60 and 6 + 7 = 13, sum is 73.
3. 58 + 19 by compensation is 58 + 20 - 1 = 77.
4. 25 + 38 using compensation is 25 + 40 - 2 = 63.
5. 62 + 25 by break-apart: 60 + 20 = 80 and 2 + 5 = 7. Sum is 87.
Mental Math Within 100
★ Part A: Multiple Choice
Circle the best answer for each question.
1. Which strategy works best for 34 + 29?
A) 34 + 30 - 1
B) 34 + 30 + 1
C) 34 - 30 + 1
D) 34 + 20 + 9 + 1
2. Which is the best break-apart step for 46 + 27?
A) 40 + 20 and 6 + 7
B) 46 + 20 + 7
C) 40 + 6 only
D) 46 - 27 and add back
3. Which approach is easiest for 58 + 19?
A) 58 + 20 - 1
B) 58 + 10 + 9
C) 58 + 19 on paper
D) 58 - 20 + 1
4. Which strategy is best for 25 + 38?
A) 25 + 40 - 2
B) 25 + 38 by ones
C) 25 + 30 + 10
D) 25 - 38 + 2
★ Part B: Fill in the Blank
Write the correct answer on each line.
1) 34 + 29 using compensation is 34 + 30 - 1 = 63.
2) 46 + 27 by break-apart: 40 + 20 = 60 and 6 + 7 = 13, sum is 73.
3) 58 + 19 by compensation is 58 + 20 - 1 = 77.
4) 25 + 38 using compensation is 25 + 40 - 2 = 63.
5) 62 + 25 by break-apart: 60 + 20 = 80 and 2 + 5 = 7. Sum is 87.
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9 Questions
12-18 minutes
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