Let's solve the addition problems on this worksheet step by step. The task is to
add two whole tens (2-digit numbers), which means we are adding multiples of 10.
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✔ Step-by-step Solutions:
We’ll add each pair of numbers:
1.
40 + 30 = 70
→ 4 tens + 3 tens = 7 tens → 70
2.
30 + 10 = 40
→ 3 tens + 1 ten = 4 tens → 40
3.
90 + 80 = 170
→ 9 tens + 8 tens = 17 tens → 170
4.
20 + 90 = 110
→ 2 tens + 9 tens = 11 tens → 110
5.
20 + 40 = 60
→ 2 tens + 4 tens = 6 tens → 60
6.
40 + 20 = 60
→ 4 tens + 2 tens = 6 tens → 60
7.
20 + 80 = 100
→ 2 tens + 8 tens = 10 tens → 100
8.
90 + 30 = 120
→ 9 tens + 3 tens = 12 tens → 120
9.
80 + 50 = 130
→ 8 tens + 5 tens = 13 tens → 130
10.
60 + 70 = 130
→ 6 tens + 7 tens = 13 tens → 130
11.
90 + 40 = 130
→ 9 tens + 4 tens = 13 tens → 130
12.
70 + 40 = 110
→ 7 tens + 4 tens = 11 tens → 110
13.
90 + 20 = 110
→ 9 tens + 2 tens = 11 tens → 110
14.
50 + 10 = 60
→ 5 tens + 1 ten = 6 tens → 60
15.
30 + 60 = 90
→ 3 tens + 6 tens = 9 tens → 90
16.
50 + 70 = 120
→ 5 tens + 7 tens = 12 tens → 120
17.
80 + 20 = 100
→ 8 tens + 2 tens = 10 tens → 100
18.
20 + 70 = 90
→ 2 tens + 7 tens = 9 tens → 90
19.
90 + 10 = 100
→ 9 tens + 1 ten = 10 tens → 100
20.
30 + 20 = 50
→ 3 tens + 2 tens = 5 tens → 50
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✔ Final Answers:
1. 70
2. 40
3. 170
4. 110
5. 60
6. 60
7. 100
8. 120
9. 130
10. 130
11. 130
12. 110
13. 110
14. 60
15. 90
16. 120
17. 100
18. 90
19. 100
20. 50
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📝 Explanation:
This worksheet helps students practice adding multiples of 10. Since all numbers end in zero, you can simplify the problem by:
- Ignoring the zeros,
- Adding the tens digits,
- Then adding back the zero.
For example:
50 + 30 → Think: 5 + 3 = 8 → Answer:
80
This builds number sense and mental math skills for second-grade students.
Let me know if you'd like a printable version or explanation for any specific problem!
Parent Tip: Review the logic above to help your child master the concept of addition of whole numbers worksheet for grade 2.
