Addition with Regrouping math worksheet for students, featuring 12 three-digit addition problems and a cute penguin illustration.

Let's solve each of the addition problems with regrouping step by step. We'll go through each one carefully, showing how to add the numbers column by column (ones, tens, hundreds), and carry over when necessary.

---

1. 246 + 483

```
246
+ 483
-----
```

- Ones place: 6 + 3 = 9 → write down 9
- Tens place: 4 + 8 = 12 → write down 2, carry over 1
- Hundreds place: 2 + 4 + 1 (carry) = 7

✔ Answer: 729

---

2. 509 + 287

```
509
+ 287
-----
```

- Ones place: 9 + 7 = 16 → write down 6, carry over 1
- Tens place: 0 + 8 + 1 = 9 → write down 9
- Hundreds place: 5 + 2 = 7

✔ Answer: 796

---

3. 452 + 356

```
452
+ 356
-----
```

- Ones place: 2 + 6 = 8
- Tens place: 5 + 5 = 10 → write down 0, carry over 1
- Hundreds place: 4 + 3 + 1 = 8

✔ Answer: 808

---

4. 225 + 846

```
225
+ 846
-----
```

- Ones place: 5 + 6 = 11 → write down 1, carry over 1
- Tens place: 2 + 4 + 1 = 7
- Hundreds place: 2 + 8 = 10 → write down 0, carry over 1 → total: 1071

Wait! Let’s do it again:

Actually:
- Hundreds: 2 + 8 = 10, plus carry from tens?

Let’s go step by step:

- Ones: 5 + 6 = 11 → write 1, carry 1
- Tens: 2 + 4 = 6, plus carry 1 = 7 → write 7
- Hundreds: 2 + 8 = 10 → write 0, carry 1 to thousands

So: 1071

✔ Answer: 1071

---

5. 349 + 375

```
349
+ 375
-----
```

- Ones: 9 + 5 = 14 → write 4, carry 1
- Tens: 4 + 7 + 1 = 12 → write 2, carry 1
- Hundreds: 3 + 3 + 1 = 7

✔ Answer: 724

---

6. 463 + 472

```
463
+ 472
-----
```

- Ones: 3 + 2 = 5
- Tens: 6 + 7 = 13 → write 3, carry 1
- Hundreds: 4 + 4 + 1 = 9

✔ Answer: 935

---

7. 487 + 357

```
487
+ 357
-----
```

- Ones: 7 + 7 = 14 → write 4, carry 1
- Tens: 8 + 5 + 1 = 14 → write 4, carry 1
- Hundreds: 4 + 3 + 1 = 8

✔ Answer: 844

---

8. 225 + 292

```
225
+ 292
-----
```

- Ones: 5 + 2 = 7
- Tens: 2 + 9 = 11 → write 1, carry 1
- Hundreds: 2 + 2 + 1 = 5

✔ Answer: 517

---

9. 597 + 290

```
597
+ 290
-----
```

- Ones: 7 + 0 = 7
- Tens: 9 + 9 = 18 → write 8, carry 1
- Hundreds: 5 + 2 + 1 = 8

✔ Answer: 887

---

10. 326 + 448

```
326
+ 448
-----
```

- Ones: 6 + 8 = 14 → write 4, carry 1
- Tens: 2 + 4 + 1 = 7
- Hundreds: 3 + 4 = 7

✔ Answer: 774

---

11. 439 + 329

```
439
+ 329
-----
```

- Ones: 9 + 9 = 18 → write 8, carry 1
- Tens: 3 + 2 + 1 = 6
- Hundreds: 4 + 3 = 7

✔ Answer: 768

---

✔ Final Answers:

1. 246 + 483 = 729
2. 509 + 287 = 796
3. 452 + 356 = 808
4. 225 + 846 = 1071
5. 349 + 375 = 724
6. 463 + 472 = 935
7. 487 + 357 = 844
8. 225 + 292 = 517
9. 597 + 290 = 887
10. 326 + 448 = 774
11. 439 + 329 = 768

---

📝 Explanation:

- Regrouping (also called carrying) happens when the sum in a column is 10 or more.
- You write down the ones digit and carry the tens digit to the next column.
- Always start from the rightmost column (ones) and move left.
- Be careful with multiple carries!

Let me know if you'd like this formatted as a printable answer sheet!