4th Grade Addition and Subtraction Worksheets with Answer Key - Free Printable

Let's solve each problem on the Addition & Subtraction Worksheet step by step. I'll go through all 20 problems and show the calculations clearly.

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Problem 1:

```
936
- 745
-----
```
Start from the right:
- 6 - 5 = 1
- 3 - 4 → can't do, borrow: 13 - 4 = 9, carry over
- 8 (after borrowing) - 7 = 1

✔ Answer: 191

---

Problem 2:

```
763
- 477
-----
```
- 3 - 7 → can't do, borrow: 13 - 7 = 6
- 5 (after borrow) - 7 → can't do, borrow: 15 - 7 = 8
- 6 (after borrow) - 4 = 2

✔ Answer: 286

---

Problem 3:

```
975
- 418
-----
```
- 5 - 8 → borrow: 15 - 8 = 7
- 6 (after borrow) - 1 = 5
- 9 - 4 = 5

✔ Answer: 557

---

Problem 4:

```
261
+ 578
-----
```
- 1 + 8 = 9
- 6 + 7 = 13 → write 3, carry 1
- 2 + 5 + 1 = 8

✔ Answer: 839

---

Problem 5:

```
625
- 495
-----
```
- 5 - 5 = 0
- 2 - 9 → can't do, borrow: 12 - 9 = 3
- 5 (after borrow) - 4 = 1

✔ Answer: 130

---

Problem 6:

```
709
- 439
-----
```
- 9 - 9 = 0
- 0 - 3 → can't do, borrow: 10 - 3 = 7
- 6 (after borrow) - 4 = 2

✔ Answer: 270

---

Problem 7:

```
654
- 543
-----
```
- 4 - 3 = 1
- 5 - 4 = 1
- 6 - 5 = 1

✔ Answer: 111

---

Problem 8:

```
273
+ 528
-----
```
- 3 + 8 = 11 → write 1, carry 1
- 7 + 2 + 1 = 10 → write 0, carry 1
- 2 + 5 + 1 = 8

✔ Answer: 801

---

Problem 9:

```
274
+ 528
-----
```
- 4 + 8 = 12 → write 2, carry 1
- 7 + 2 + 1 = 10 → write 0, carry 1
- 2 + 5 + 1 = 8

✔ Answer: 802

---

Problem 10:

```
347
- 289
-----
```
- 7 - 9 → borrow: 17 - 9 = 8
- 3 (after borrow) - 8 → borrow: 13 - 8 = 5
- 2 (after borrow) - 2 = 0

✔ Answer: 58

---

Problem 11:

```
999
+ 339
-----
```
- 9 + 9 = 18 → write 8, carry 1
- 9 + 3 + 1 = 13 → write 3, carry 1
- 9 + 3 + 1 = 13 → write 3, carry 1
- Carry over: 1

✔ Answer: 1338

---

Problem 12:

```
639
- 165
-----
```
- 9 - 5 = 4
- 3 - 6 → borrow: 13 - 6 = 7
- 5 (after borrow) - 1 = 4

✔ Answer: 474

---

Problem 13:

```
352
- 109
-----
```
- 2 - 9 → borrow: 12 - 9 = 3
- 4 (after borrow) - 0 = 4
- 3 - 1 = 2

✔ Answer: 243

---

Problem 14:

```
356
+ 749
-----
```
- 6 + 9 = 15 → write 5, carry 1
- 5 + 4 + 1 = 10 → write 0, carry 1
- 3 + 7 + 1 = 11 → write 1, carry 1
- Final carry: 1

✔ Answer: 1105

---

Problem 15:

```
238
+ 597
-----
```
- 8 + 7 = 15 → write 5, carry 1
- 3 + 9 + 1 = 13 → write 3, carry 1
- 2 + 5 + 1 = 8

✔ Answer: 835

---

Problem 16:

```
359
- 150
-----
```
- 9 - 0 = 9
- 5 - 5 = 0
- 3 - 1 = 2

✔ Answer: 209

---

Problem 17:

```
677
+ 970
-----
```
- 7 + 0 = 7
- 7 + 7 = 14 → write 4, carry 1
- 6 + 9 + 1 = 16 → write 6, carry 1
- Final carry: 1

✔ Answer: 1647

---

Problem 18:

```
109
+ 889
-----
```
- 9 + 9 = 18 → write 8, carry 1
- 0 + 8 + 1 = 9
- 1 + 8 = 9

✔ Answer: 998

---

Problem 19:

```
374
+ 465
-----
```
- 4 + 5 = 9
- 7 + 6 = 13 → write 3, carry 1
- 3 + 4 + 1 = 8

✔ Answer: 839

---

Problem 20:

```
749
- 664
-----
```
- 9 - 4 = 5
- 4 - 6 → borrow: 14 - 6 = 8
- 6 (after borrow) - 6 = 0

✔ Answer: 85

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✔ Final Answers:

| # | Problem | Answer |
|---|--------|--------|
| 1 | 936 - 745 | 191 |
| 2 | 763 - 477 | 286 |
| 3 | 975 - 418 | 557 |
| 4 | 261 + 578 | 839 |
| 5 | 625 - 495 | 130 |
| 6 | 709 - 439 | 270 |
| 7 | 654 - 543 | 111 |
| 8 | 273 + 528 | 801 |
| 9 | 274 + 528 | 802 |
|10 | 347 - 289 | 58 |
|11 | 999 + 339 | 1338 |
|12 | 639 - 165 | 474 |
|13 | 352 - 109 | 243 |
|14 | 356 + 749 | 1105 |
|15 | 238 + 597 | 835 |
|16 | 359 - 150 | 209 |
|17 | 677 + 970 | 1647 |
|18 | 109 + 889 | 998 |
|19 | 374 + 465 | 839 |
|20 | 749 - 664 | 85 |

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Let me know if you'd like this in a printable format or need explanations for any specific problem!