Let's solve the problem step by step. The task is to
estimate the sum or difference by
rounding off the numbers to the nearest hundred (or thousand, depending on the size of the numbers), then performing the operation.
We'll go through each one carefully.
---
🔹 Estimate the Sum
We round each number to the
nearest hundred unless it's large enough that rounding to the
nearest thousand makes more sense. We'll use
nearest hundred for most cases, but adjust if needed.
---
1.
3,854 + 6,028
- Round 3,854 → 3,900 (nearest hundred)
- Round 6,028 → 6,000 (nearest hundred)
- Estimated sum:
3,900 + 6,000 = 9,900
✔ Answer: 3,900 + 6,000 = 9,900
---
2.
8,322 + 1,103
- 8,322 → 8,300
- 1,103 → 1,100
- 8,300 + 1,100 =
9,400
✔ Answer: 8,300 + 1,100 = 9,400
---
3.
67,551 + 85,302
These are larger numbers — round to
nearest thousand.
- 67,551 → 68,000
- 85,302 → 85,000
- 68,000 + 85,000 =
153,000
✔ Answer: 68,000 + 85,000 = 153,000
---
4.
10,364 + 59,493
Round to nearest
thousand:
- 10,364 → 10,000
- 59,493 → 59,000
- 10,000 + 59,000 =
69,000
✔ Answer: 10,000 + 59,000 = 69,000
---
5.
94,650 + 2,113
Round to nearest
thousand:
- 94,650 → 95,000
- 2,113 → 2,000
- 95,000 + 2,000 =
97,000
✔ Answer: 95,000 + 2,000 = 97,000
---
🔹 Estimate the Difference
Now estimate the differences using similar rounding rules.
---
6.
9,493 - 2,324
Round to nearest
hundred:
- 9,493 → 9,500
- 2,324 → 2,300
- 9,500 - 2,300 =
7,200
✔ Answer: 9,500 - 2,300 = 7,200
---
7.
5,036 - 1,945
- 5,036 → 5,000
- 1,945 → 1,900
- 5,000 - 1,900 =
3,100
✔ Answer: 5,000 - 1,900 = 3,100
---
8.
68,931 - 11,585
Round to
nearest thousand:
- 68,931 → 69,000
- 11,585 → 12,000
- 69,000 - 12,000 =
57,000
✔ Answer: 69,000 - 12,000 = 57,000
---
9.
74,832 - 15,002
- 74,832 → 75,000
- 15,002 → 15,000
- 75,000 - 15,000 =
60,000
✔ Answer: 75,000 - 15,000 = 60,000
---
10.
35,846 - 5,394
- 35,846 → 36,000
- 5,394 → 5,000
- 36,000 - 5,000 =
31,000
✔ Answer: 36,000 - 5,000 = 31,000
---
✔ Final Answers:
####
Estimate the sum:
1. 3,854 + 6,028 →
3,900 + 6,000 = 9,900
2. 8,322 + 1,103 →
8,300 + 1,100 = 9,400
3. 67,551 + 85,302 →
68,000 + 85,000 = 153,000
4. 10,364 + 59,493 →
10,000 + 59,000 = 69,000
5. 94,650 + 2,113 →
95,000 + 2,000 = 97,000
####
Estimate the difference:
6. 9,493 - 2,324 →
9,500 - 2,300 = 7,200
7. 5,036 - 1,945 →
5,000 - 1,900 = 3,100
8. 68,931 - 11,585 →
69,000 - 12,000 = 57,000
9. 74,832 - 15,002 →
75,000 - 15,000 = 60,000
10. 35,846 - 5,394 →
36,000 - 5,000 = 31,000
---
💡
Tip: When estimating, always consider the place value and round to a convenient number (like nearest 100 or 1,000) based on the size of the numbers. This helps make mental math easier while still giving a good approximation.
Parent Tip: Review the logic above to help your child master the concept of estimation worksheets.
