Let's solve each addition problem on the worksheet step by step, focusing on
adding 3-digit and 2-digit numbers with regrouping.
We'll go through each box one at a time:
---
1. 23 + 138
```
23
+138
----
161
```
- Add ones: 3 + 8 = 11 → write 1, carry over 1
- Add tens: 2 + 3 + 1 (carry) = 6
- Add hundreds: 1
→
Answer: 161
---
2. 55 + 215
```
55
+215
----
270
```
- Ones: 5 + 5 = 10 → write 0, carry 1
- Tens: 5 + 1 + 1 = 7
- Hundreds: 2
→
Answer: 270
---
3. 15 + 329
```
15
+329
----
344
```
- Ones: 5 + 9 = 14 → write 4, carry 1
- Tens: 1 + 2 + 1 = 4
- Hundreds: 3
→
Answer: 344
---
4. 717 + 14
```
717
+ 14
----
731
```
- Ones: 7 + 4 = 11 → write 1, carry 1
- Tens: 1 + 1 + 1 = 3
- Hundreds: 7
→
Answer: 731
---
5. 63 + 765
```
63
+765
----
828
```
- Ones: 3 + 5 = 8
- Tens: 6 + 6 = 12 → write 2, carry 1
- Hundreds: 7 + 0 + 1 = 8
→
Answer: 828
---
6. 217 + 85
```
217
+ 85
----
302
```
- Ones: 7 + 5 = 12 → write 2, carry 1
- Tens: 1 + 8 + 1 = 10 → write 0, carry 1
- Hundreds: 2 + 0 + 1 = 3
→
Answer: 302
---
7. 414 + 58
```
414
+ 58
----
472
```
- Ones: 4 + 8 = 12 → write 2, carry 1
- Tens: 1 + 5 + 1 = 7
- Hundreds: 4
→
Answer: 472
---
8. 75 + 194
```
75
+194
----
269
```
- Ones: 5 + 4 = 9
- Tens: 7 + 9 = 16 → write 6, carry 1
- Hundreds: 0 + 1 + 1 = 2
→
Answer: 269
---
9. 786 + 23
```
786
+ 23
----
809
```
- Ones: 6 + 3 = 9
- Tens: 8 + 2 = 10 → write 0, carry 1
- Hundreds: 7 + 0 + 1 = 8
→
Answer: 809
---
10. 791 + 54
```
791
+ 54
----
845
```
- Ones: 1 + 4 = 5
- Tens: 9 + 5 = 14 → write 4, carry 1
- Hundreds: 7 + 0 + 1 = 8
→
Answer: 845
---
11. 84 + 792
```
84
+792
----
876
```
- Ones: 4 + 2 = 6
- Tens: 8 + 9 = 17 → write 7, carry 1
- Hundreds: 0 + 7 + 1 = 8
→
Answer: 876
---
12. 572 + 36
```
572
+ 36
----
608
```
- Ones: 2 + 6 = 8
- Tens: 7 + 3 = 10 → write 0, carry 1
- Hundreds: 5 + 0 + 1 = 6
→
Answer: 608
---
13. 598 + 26
```
598
+ 26
----
624
```
- Ones: 8 + 6 = 14 → write 4, carry 1
- Tens: 9 + 2 + 1 = 12 → write 2, carry 1
- Hundreds: 5 + 0 + 1 = 6
→
Answer: 624
---
14. 199 + 64
```
199
+ 64
----
263
```
- Ones: 9 + 4 = 13 → write 3, carry 1
- Tens: 9 + 6 + 1 = 16 → write 6, carry 1
- Hundreds: 1 + 0 + 1 = 2
→
Answer: 263
---
15. 129 + 78
```
129
+ 78
----
207
```
- Ones: 9 + 8 = 17 → write 7, carry 1
- Tens: 2 + 7 + 1 = 10 → write 0, carry 1
- Hundreds: 1 + 0 + 1 = 2
→
Answer: 207
---
16. 55 + 769
```
55
+769
----
824
```
- Ones: 5 + 9 = 14 → write 4, carry 1
- Tens: 5 + 6 + 1 = 12 → write 2, carry 1
- Hundreds: 0 + 7 + 1 = 8
→
Answer: 824
---
✔ Final Answers:
1. 161
2. 270
3. 344
4. 731
5. 828
6. 302
7. 472
8. 269
9. 809
10. 845
11. 876
12. 608
13. 624
14. 263
15. 207
16. 824
---
📝 Explanation:
- We added the numbers column by column:
ones, then
tens, then
hundreds.
- When the sum in any column is
10 or more, we
regroup (carry over) to the next higher place value.
- This process ensures accurate addition even when digits exceed 9 in a column.
Let me know if you'd like this as a printable answer sheet!
Parent Tip: Review the logic above to help your child master the concept of addition worksheet for 3rd grade.
