Front-End Estimation worksheet for practicing rounding and addition/subtraction with two and three-digit numbers.

Let's solve the Front-End Estimation problems step by step.

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🔍 What is Front-End Estimation?

Front-end estimation means:
- You only use the numbers in the leftmost (left-most) column.
- For 2-digit numbers, you round to the nearest ten.
- For 3-digit numbers, you round to the nearest hundred.
- Then, add or subtract those rounded numbers.

> Example given:
> 64 + 22 → Round 64 to 60, 22 to 20 → 60 + 20 = 80
> 578 - 241 → Round 578 to 600, 241 to 200 → 600 - 200 = 400

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Now let’s go through each problem:

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🔹 Pink Box Problems (2-digit numbers → round to nearest ten)

1. 55 + 31
→ 55 → 60, 31 → 30
→ 60 + 30 = 90

2. 67 + 11
→ 67 → 70, 11 → 10
→ 70 + 10 = 80

3. 98 + 46
→ 98 → 100, 46 → 50
→ 100 + 50 = 150

4. 28 + 74
→ 28 → 30, 74 → 70
→ 30 + 70 = 100

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🔹 Blue Box Problems (2-digit numbers → round to nearest ten)

5. 47 - 34
→ 47 → 50, 34 → 30
→ 50 - 30 = 20

6. 65 - 15
→ 65 → 70, 15 → 10
→ 70 - 10 = 60

7. 91 - 28
→ 91 → 90, 28 → 30
→ 90 - 30 = 60

8. 89 - 44
→ 89 → 90, 44 → 40
→ 90 - 40 = 50

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🔹 Green Box Problems (3-digit numbers → round to nearest hundred)

9. 792 + 136
→ 792 → 800, 136 → 100
→ 800 + 100 = 900

10. 949 + 267
→ 949 → 900, 267 → 300
→ 900 + 300 = 1200

11. 452 + 631
→ 452 → 500, 631 → 600
→ 500 + 600 = 1100

12. 585 + 842
→ 585 → 600, 842 → 800
→ 600 + 800 = 1400

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🔹 Yellow Box Problems (3-digit numbers → round to nearest hundred)

13. 389 - 198
→ 389 → 400, 198 → 200
→ 400 - 200 = 200

14. 867 - 491
→ 867 → 900, 491 → 500
→ 900 - 500 = 400

15. 511 - 284
→ 511 → 500, 284 → 300
→ 500 - 300 = 200

16. 738 - 684
→ 738 → 700, 684 → 700
→ 700 - 700 = 0

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✔ Final Answers:

| Problem | Answer |
|--------|--------|
| 55 + 31 | 90 |
| 67 + 11 | 80 |
| 98 + 46 | 150 |
| 28 + 74 | 100 |
| 47 - 34 | 20 |
| 65 - 15 | 60 |
| 91 - 28 | 60 |
| 89 - 44 | 50 |
| 792 + 136 | 900 |
| 949 + 267 | 1200 |
| 452 + 631 | 1100 |
| 585 + 842 | 1400 |
| 389 - 198 | 200 |
| 867 - 491 | 400 |
| 511 - 284 | 200 |
| 738 - 684 | 0 |

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