Addition worksheet with multiple three-digit addition problems for practice.

I'll solve each addition problem step by step, working through them carefully.

Problem 1: 996 + 978
- Ones place: 6 + 8 = 14 (write 4, carry 1)
- Tens place: 9 + 7 + 1 = 17 (write 7, carry 1)
- Hundreds place: 9 + 9 + 1 = 19
- Answer: 1,974

Problem 2: 896 + 968
- Ones place: 6 + 8 = 14 (write 4, carry 1)
- Tens place: 9 + 6 + 1 = 16 (write 6, carry 1)
- Hundreds place: 8 + 9 + 1 = 18
- Answer: 1,864

Problem 3: 795 + 998
- Ones place: 5 + 8 = 13 (write 3, carry 1)
- Tens place: 9 + 9 + 1 = 19 (write 9, carry 1)
- Hundreds place: 7 + 9 + 1 = 17
- Answer: 1,793

Problem 4: 598 + 958
- Ones place: 8 + 8 = 16 (write 6, carry 1)
- Tens place: 9 + 5 + 1 = 15 (write 5, carry 1)
- Hundreds place: 5 + 9 + 1 = 15
- Answer: 1,556

Problem 5: 597 + 938
- Ones place: 7 + 8 = 15 (write 5, carry 1)
- Tens place: 9 + 3 + 1 = 13 (write 3, carry 1)
- Hundreds place: 5 + 9 + 1 = 15
- Answer: 1,535

Problem 6: 596 + 928
- Ones place: 6 + 8 = 14 (write 4, carry 1)
- Tens place: 9 + 2 + 1 = 12 (write 2, carry 1)
- Hundreds place: 5 + 9 + 1 = 15
- Answer: 1,524

Problem 7: 595 + 968
- Ones place: 5 + 8 = 13 (write 3, carry 1)
- Tens place: 9 + 6 + 1 = 16 (write 6, carry 1)
- Hundreds place: 5 + 9 + 1 = 15
- Answer: 1,563

Problem 8: 594 + 978
- Ones place: 4 + 8 = 12 (write 2, carry 1)
- Tens place: 9 + 7 + 1 = 17 (write 7, carry 1)
- Hundreds place: 5 + 9 + 1 = 15
- Answer: 1,572

Problem 9: 593 + 998
- Ones place: 3 + 8 = 11 (write 1, carry 1)
- Tens place: 9 + 9 + 1 = 19 (write 9, carry 1)
- Hundreds place: 5 + 9 + 1 = 15
- Answer: 1,591

Problem 10: 599 + 978
- Ones place: 9 + 8 = 17 (write 7, carry 1)
- Tens place: 9 + 7 + 1 = 17 (write 7, carry 1)
- Hundreds place: 5 + 9 + 1 = 15
- Answer: 1,577

Problem 11: 678 + 543
- Ones place: 8 + 3 = 11 (write 1, carry 1)
- Tens place: 7 + 4 + 1 = 12 (write 2, carry 1)
- Hundreds place: 6 + 5 + 1 = 12
- Answer: 1,221

Problem 12: 876 + 555
- Ones place: 6 + 5 = 11 (write 1, carry 1)
- Tens place: 7 + 5 + 1 = 13 (write 3, carry 1)
- Hundreds place: 8 + 5 + 1 = 14
- Answer: 1,431

Final Answer:
1. 1,974
2. 1,864
3. 1,793
4. 1,556
5. 1,535
6. 1,524
7. 1,563
8. 1,572
9. 1,591
10. 1,577
11. 1,221
12. 1,431