Let’s go through each problem one by one, checking whether the given estimate is correct. Estimating quotients usually involves rounding the dividend and divisor to numbers that are easier to divide — often to the nearest ten or hundred — while keeping the estimate reasonably close to the actual value.
---
Problem 1:
>
Given:
> 123 ÷ 63 ≈ 180 ÷ 60 = 3
>
Check: Is this a good estimate?
- Actual values: 123 ÷ 63 ≈ 1.95 (close to 2)
- Estimated: 180 ÷ 60 = 3 → This is too high.
- Why? 123 was rounded *up* to 180 (which is a big jump), while 63 was only slightly rounded down to 60. This overestimates the quotient.
✔ Correct Estimate:
Round 123 to 120 and 63 to 60 →
120 ÷ 60 = 2
✔️ So, the original estimate of 3 is
incorrect.
---
Problem 2:
>
Given:
> 345 ÷ 169 ≈ 300 ÷ 100 = 3
>
Check: Is this a good estimate?
- Actual: 345 ÷ 169 ≈ 2.04 (close to 2)
- Estimated: 300 ÷ 100 = 3 → Again, too high.
- Why? 345 was rounded down to 300, but 169 was rounded down *more* to 100 — which makes the divisor too small, so the quotient becomes too large.
✔ Better Estimate:
Round 345 to 350 and 169 to 170 →
350 ÷ 170 ≈ 2.06 → Close to 2
Or even simpler: Round 345 to 340 and 169 to 170 → 340 ÷ 170 = 2
✔️ So, the original estimate of 3 is
incorrect.
---
Problem 3:
>
Given:
> 482 ÷ 64 ≈ 500 ÷ 50 = 10
>
Check: Is this a good estimate?
- Actual: 482 ÷ 64 ≈ 7.53
- Estimated: 500 ÷ 50 = 10 → Way too high!
- Why? 64 was incorrectly rounded down to 50 (which is not close). 64 should be rounded to 60 or 65 for better accuracy.
✔ Better Estimate:
Round 482 to 480 and 64 to 60 →
480 ÷ 60 = 8
Or 482 ÷ 64 ≈ 480 ÷ 64 ≈ 7.5 → still close to 8.
✔️ So, the original estimate of 10 is
incorrect.
---
Problem 4:
>
Given:
> 239 ÷ 124 ≈ 240 ÷ 120 = 2
>
Check: Is this a good estimate?
- Actual: 239 ÷ 124 ≈ 1.93 (very close to 2)
- Estimated: 240 ÷ 120 = 2 → Perfect!
This is a great estimate because:
- 239 ≈ 240 (rounding up slightly)
- 124 ≈ 120 (rounding down slightly)
→ The rounding errors offset each other, giving a very accurate estimate.
✔️ So, this estimate is
correct.
---
##
✔ Final Answers:
| Problem | YES / NO | Correct Estimate (if NO) |
|---------|----------|---------------------------|
| 1 |
NO | 120 ÷ 60 = 2 |
| 2 |
NO | 350 ÷ 170 ≈ 2 or 340 ÷ 170 = 2 |
| 3 |
NO | 480 ÷ 60 = 8 |
| 4 |
YES | — |
---
💡
Tip for Estimating Quotients:
Always try to round both numbers to compatible numbers (like multiples of 10 or 100) that are easy to divide, and make sure your rounding doesn’t distort the result too much. If you round the divisor down too much, your quotient will be too high — and vice versa.
Let me know if you want to see visual number line estimates or step-by-step long division checks!
Parent Tip: Review the logic above to help your child master the concept of estimate quotients worksheet.