Fifth Grade Estimation Worksheets - Free Printable

Let's solve each of the addition problems on the worksheet step by step. The task asks us to:

1. Estimate the sum (round the numbers to the nearest hundred or ten, depending on what makes estimation easier).
2. Calculate the actual sum.
3. Compare the estimate with the actual amount.

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Problem 1: 145 + 325

- Estimate:
Round 145 → 150
Round 325 → 300
Estimate: 150 + 300 = 450

- Actual:
145 + 325 = 470

✔ Estimate: 450 | Actual: 470

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Problem 2: 572 + 227

- Estimate:
Round 572 → 600
Round 227 → 200
Estimate: 600 + 200 = 800

- Actual:
572 + 227 = 799

✔ Estimate: 800 | Actual: 799

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Problem 3: 166 + 622

- Estimate:
Round 166 → 200
Round 622 → 600
Estimate: 200 + 600 = 800

- Actual:
166 + 622 = 788

✔ Estimate: 800 | Actual: 788

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Problem 4: 608 + 321

- Estimate:
Round 608 → 600
Round 321 → 300
Estimate: 600 + 300 = 900

- Actual:
608 + 321 = 929

✔ Estimate: 900 | Actual: 929

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Problem 5: 455 + 213

- Estimate:
Round 455 → 500
Round 213 → 200
Estimate: 500 + 200 = 700

- Actual:
455 + 213 = 668

✔ Estimate: 700 | Actual: 668

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Problem 6: 326 + 321

- Estimate:
Round 326 → 300
Round 321 → 300
Estimate: 300 + 300 = 600

- Actual:
326 + 321 = 647

✔ Estimate: 600 | Actual: 647

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Problem 7: 309 + 381

- Estimate:
Round 309 → 300
Round 381 → 400
Estimate: 300 + 400 = 700

- Actual:
309 + 381 = 690

✔ Estimate: 700 | Actual: 690

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Problem 8: 486 + 201

- Estimate:
Round 486 → 500
Round 201 → 200
Estimate: 500 + 200 = 700

- Actual:
486 + 201 = 687

✔ Estimate: 700 | Actual: 687

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✔ Final Answers Summary:

| Problem | Estimate | Actual |
|--------|----------|--------|
| 1 | 450 | 470 |
| 2 | 800 | 799 |
| 3 | 800 | 788 |
| 4 | 900 | 929 |
| 5 | 700 | 668 |
| 6 | 600 | 647 |
| 7 | 700 | 690 |
| 8 | 700 | 687 |

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🔍 Explanation:

- Estimation helps us quickly get a ballpark figure without doing exact calculations.
- We round each number to the nearest hundred (or sometimes ten, if it’s closer) to make mental math easier.
- Then we compute the actual sum using standard addition.
- Comparing both shows how close our estimate was — this builds number sense and checking skills.

This is a great exercise for students to practice rounding and estimation in real-world contexts! 🎯