Add/Subtract Estimation Worksheet - Free Printable

Absolutely! Let’s solve each problem step by step — first by estimating (rounding numbers to make them easier to add or subtract), then by calculating the actual sum or difference, so you can see how close your estimate was.

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Problem 1:

Estimate:
45 → 50
37 → 40
Estimated sum = 50 + 40 = 90

Actual calculation:
45 + 37 = 82

✔ Estimate: 90 | Actual: 82 → Difference: 8

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Problem 2:

Estimate:
Round to nearest ten or hundred? Since these are 3-digit numbers, let’s round to the nearest ten.
372 → 370
439 → 440
Estimated sum = 370 + 440 = 810

Actual calculation:
372 + 439 = 811

✔ Estimate: 810 | Actual: 811 → Difference: 1 — Very close!

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Problem 3:

Estimate:
409 → 410
379 → 380
Estimated sum = 410 + 380 = 790

Actual calculation:
409 + 379 = 788

✔ Estimate: 790 | Actual: 788 → Difference: 2

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Problem 4:

Estimate:
825 → 830
199 → 200
Estimated sum = 830 + 200 = 1030

Actual calculation:
825 + 199 = 1024

✔ Estimate: 1030 | Actual: 1024 → Difference: 6

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Problem 5:

Estimate:
941 → 940
458 → 460
Estimated sum = 940 + 460 = 1400

Actual calculation:
941 + 458 = 1399

✔ Estimate: 1400 | Actual: 1399 → Difference: 1 — Perfect!

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Problem 6:

Estimate:
68 → 70
24 → 20
Estimated difference = 70 - 20 = 50

Actual calculation:
68 - 24 = 44

✔ Estimate: 50 | Actual: 44 → Difference: 6

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Problem 7:

Estimate:
296 → 300
152 → 150
Estimated difference = 300 - 150 = 150

Actual calculation:
296 - 152 = 144

✔ Estimate: 150 | Actual: 144 → Difference: 6

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Problem 8:

Estimate:
582 → 580
326 → 330
Estimated difference = 580 - 330 = 250

Actual calculation:
582 - 326 = 256

✔ Estimate: 250 | Actual: 256 → Difference: 6

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Problem 9:

Estimate:
819 → 820
539 → 540
Estimated difference = 820 - 540 = 280

Actual calculation:
819 - 539 = 280

✔ Estimate: 280 | Actual: 280 → Difference: 0 — Exact match!

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Problem 10:

Estimate:
947 → 950
533 → 530
Estimated difference = 950 - 530 = 420

Actual calculation:
947 - 533 = 414

✔ Estimate: 420 | Actual: 414 → Difference: 6

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## ✔ Final Answer Summary:

| Problem | Estimate | Actual | Difference |
|---------|----------|--------|----------|
| 1 | 90 | 82 | 8 |
| 2 | 810 | 811 | 1 |
| 3 | 790 | 788 | 2 |
| 4 | 1030 | 1024 | 6 |
| 5 | 1400 | 1399 | 1 |
| 6 | 50 | 44 | 6 |
| 7 | 150 | 144 | 6 |
| 8 | 250 | 256 | 6 |
| 9 | 280 | 280 | 0 |
| 10 | 420 | 414 | 6 |

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## 💡 Explanation:
- Estimation helps you quickly get a “ballpark” answer before doing exact math.
- We usually round to the nearest ten or hundred depending on the size of the numbers.
- The goal is to see how close your estimate is — small differences mean good estimation skills!
- Estimation is useful in real life for checking if your exact answer makes sense (e.g., if you estimate 100 and get 500, you probably made a mistake).

Let me know if you want to practice more or need help with rounding rules! 😊