3-digit addition multi-addends worksheet for 2nd grade, designed to practice adding three numbers.

Let's solve each of the addition problems on this worksheet step by step. This is a 3-digit addition with multiple addends sheet, meaning we are adding two or three 3-digit numbers together.

We’ll go through each problem carefully, aligning digits by place value (ones, tens, hundreds), and carry over when needed.

---

1) 327 + 468

```
327
+ 468
-----
795
```
- 7 + 8 = 15 → write 5, carry 1
- 2 + 6 + 1 = 9
- 3 + 4 = 7

✔ 795

---

2) 536 + 482

```
536
+ 482
-----
1018
```
- 6 + 2 = 8
- 3 + 8 = 11 → write 1, carry 1
- 5 + 4 + 1 = 10

✔ 1018

---

3) 731 + 566

```
731
+ 566
-----
1297
```
- 1 + 6 = 7
- 3 + 6 = 9
- 7 + 5 = 12

✔ 1297

---

4) 629 + 478

```
629
+ 478
-----
1107
```
- 9 + 8 = 17 → write 7, carry 1
- 2 + 7 + 1 = 10 → write 0, carry 1
- 6 + 4 + 1 = 11

✔ 1107

---

5) 397 + 254

```
397
+ 254
-----
651
```
- 7 + 4 = 11 → write 1, carry 1
- 9 + 5 + 1 = 15 → write 5, carry 1
- 3 + 2 + 1 = 6

✔ 651

---

6) 673 + 485

```
673
+ 485
-----
1158
```
- 3 + 5 = 8
- 7 + 8 = 15 → write 5, carry 1
- 6 + 4 + 1 = 11

✔ 1158

---

7) 379 + 256

```
379
+ 256
-----
635
```
- 9 + 6 = 15 → write 5, carry 1
- 7 + 5 + 1 = 13 → write 3, carry 1
- 3 + 2 + 1 = 6

✔ 635

---

8) 905 + 476

```
905
+ 476
-----
1381
```
- 5 + 6 = 11 → write 1, carry 1
- 0 + 7 + 1 = 8
- 9 + 4 = 13

✔ 1381

---

9) 324 + 156 + 123

Add step by step:

First:
```
324
+ 156
-----
480
```

Then:
```
480
+ 123
-----
603
```

✔ 603

---

10) 403 + 256 + 127

Step 1:
```
403
+ 256
-----
659
```

Step 2:
```
659
+ 127
-----
786
```

✔ 786

---

11) 341 + 137 + 65

Step 1:
```
341
+ 137
-----
478
```

Step 2:
```
478
+ 65
-----
543
```

✔ 543

---

12) 251 + 174 + 58

Step 1:
```
251
+ 174
-----
425
```

Step 2:
```
425
+ 58
-----
483
```

✔ 483

---

13) 325 + 273 + 106

Step 1:
```
325
+ 273
-----
598
```

Step 2:
```
598
+ 106
-----
704
```

✔ 704

---

14) 427 + 152 + 216

Step 1:
```
427
+ 152
-----
579
```

Step 2:
```
579
+ 216
-----
795
```

✔ 795

---

15) 526 + 164 + 75

Step 1:
```
526
+ 164
-----
690
```

Step 2:
```
690
+ 75
-----
765
```

✔ 765

---

16) 438 + 361 + 46

Step 1:
```
438
+ 361
-----
799
```

Step 2:
```
799
+ 46
-----
845
```

✔ 845

---

17) 481 + 157 + 232

Step 1:
```
481
+ 157
-----
638
```

Step 2:
```
638
+ 232
-----
870
```

✔ 870

---

18) 624 + 315 + 46

Step 1:
```
624
+ 315
-----
939
```

Step 2:
```
939
+ 46
-----
985
```

✔ 985

---

19) 306 + 245 + 77

Step 1:
```
306
+ 245
-----
551
```

Step 2:
```
551
+ 77
-----
628
```

✔ 628

---

20) 432 + 371 + 258

Step 1:
```
432
+ 371
-----
803
```

Step 2:
```
803
+ 258
-----
1061
```

✔ 1061

---

✔ Final Answers:

| Problem | Answer |
|--------|--------|
| 1) | 795 |
| 2) | 1018 |
| 3) | 1297 |
| 4) | 1107 |
| 5) | 651 |
| 6) | 1158 |
| 7) | 635 |
| 8) | 1381 |
| 9) | 603 |
| 10) | 786 |
| 11) | 543 |
| 12) | 483 |
| 13) | 704 |
| 14) | 795 |
| 15) | 765 |
| 16) | 845 |
| 17) | 870 |
| 18) | 985 |
| 19) | 628 |
| 20) | 1061 |

---

📝 Tips for Solving These Problems:

- Always align digits by place value (ones under ones, tens under tens, etc.)
- Add from right to left
- Carry over any number greater than 9 to the next column
- For three addends, add two first, then add the third

This worksheet helps build strong foundational arithmetic skills — especially place value understanding and regrouping (carrying).

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