Math worksheet for estimating sums by rounding numbers to the nearest hundred.

Let’s work through each problem step by step.

We are told to estimate the sum by rounding each number to the nearest hundred, then add the rounded numbers.

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Problem 1: 189 + 334

- 189 → rounds to 200 (since 89 is closer to 100 than 0)
- 334 → rounds to 300 (since 34 is closer to 0 than 100)
- Estimate: 200 + 300 = 500

✔ Matches the example given.

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Problem 2: 441 + 323

- 441 → 400 (41 is closer to 0 than 100)
- 323 → 300 (23 is closer to 0 than 100)
- Estimate: 400 + 300 = 700

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Problem 3: 252 + 368

- 252 → 300 (52 is closer to 100 than 0 — note: 50 and above rounds up!)
- 368 → 400 (68 is closer to 100)
- Estimate: 300 + 400 = 700

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Problem 4: 363 + 429

- 363 → 400 (63 ≥ 50 → round up)
- 429 → 400 (29 < 50 → round down)
- Estimate: 400 + 400 = 800

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Problem 5: 598 + 176

- 598 → 600 (98 is very close to 100 → round up)
- 176 → 200 (76 ≥ 50 → round up)
- Estimate: 600 + 200 = 800

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Problem 6: 625 + 238

- 625 → 600 (25 < 50 → round down? Wait — actually, 25 is exactly halfway. Standard rule: round to nearest even or always up? In elementary math, usually 50+ rounds up. But 25 is less than 50 → so 600.
Wait — let’s double-check: 625 is between 600 and 700. Distance to 600 is 25, to 700 is 75 → so closer to 600 → 600
- 238 → 200 (38 < 50 → round down)
- Estimate: 600 + 200 = 800

But wait — some curricula teach that 50 and above rounds up. 25 is below 50 → still 600.

Actually, 625: tens digit is 2 → less than 5 → round down → 600. Correct.

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Problem 7: 324 + 150

- 324 → 300 (24 < 50 → round down)
- 150 → 200 (50 → round up — standard rule: 50 and above rounds up)
- Estimate: 300 + 200 = 500

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Problem 8: 716 + 202

- 716 → 700 (16 < 50 → round down)
- 202 → 200 (02 < 50 → round down)
- Estimate: 700 + 200 = 900

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Problem 9: 137 + 381

- 137 → 100 (37 < 50 → round down)
- 381 → 400 (81 ≥ 50 → round up)
- Estimate: 100 + 400 = 500

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Problem 10: 681 + 99

- 681 → 700 (81 ≥ 50 → round up)
- 99 → 100 (99 is very close to 100 → round up)
- Estimate: 700 + 100 = 800

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Problem 11: 528 + 145

- 528 → 500 (28 < 50 → round down)
- 145 → 100 (45 < 50 → round down) — Wait! 45 is less than 50 → yes, round down to 100.
But some might argue 45 is halfway — but standard is: 0–49 round down, 50–99 round up.
So 145 → 100.
- Estimate: 500 + 100 = 600

Wait — let me check again: 145 is 45 away from 100, 55 away from 200 → so closer to 100 → correct.

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Problem 12: 848 + 136

- 848 → 800 (48 < 50 → round down)
- 136 → 100 (36 < 50 → round down)
- Estimate: 800 + 100 = 900

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Now let’s list all answers clearly:

1. 189 + 334 → 200 + 300 = 500
2. 441 + 323 → 400 + 300 = 700
3. 252 + 368 → 300 + 400 = 700
4. 363 + 429 → 400 + 400 = 800
5. 598 + 176 → 600 + 200 = 800
6. 625 + 238 → 600 + 200 = 800
7. 324 + 150 → 300 + 200 = 500
8. 716 + 202 → 700 + 200 = 900
9. 137 + 381 → 100 + 400 = 500
10. 681 + 99 → 700 + 100 = 800
11. 528 + 145 → 500 + 100 = 600
12. 848 + 136 → 800 + 100 = 900

All calculations verified.

Final Answer:
500, 700, 700, 800, 800, 800, 500, 900, 500, 800, 600, 900