Math worksheet for estimating differences by rounding numbers.
A math worksheet titled "Estimating the difference" with exercises for rounding numbers to the nearest hundred and thousand before subtraction.
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Step-by-step solution for: Estimating Differences Worksheets - 15 Worksheets Library
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Show Answer Key & Explanations
Step-by-step solution for: Estimating Differences Worksheets - 15 Worksheets Library
Let’s solve each problem step by step.
We are asked to estimate the difference by rounding numbers — first to the nearest hundred, then to the nearest thousand.
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Part 1: Round to the nearest hundred
Rule: Look at the tens digit. If it’s 5 or more, round up. If less than 5, round down.
1. 476 - 238
- 476 → tens digit is 7 → round up → 500
- 238 → tens digit is 3 → round down → 200
- Estimate: 500 - 200 = 300
2. 276 - 138
- 276 → tens digit 7 → round up → 300
- 138 → tens digit 3 → round down → 100
- Estimate: 300 - 100 = 200
3. 342 - 145
- 342 → tens digit 4 → round down → 300
- 145 → tens digit 4 → round down → 100
- Estimate: 300 - 100 = 200
4. 861 - 345
- 861 → tens digit 6 → round up → 900
- 345 → tens digit 4 → round down → 300
- Estimate: 900 - 300 = 600
5. 676 - 312
- 676 → tens digit 7 → round up → 700
- 312 → tens digit 1 → round down → 300
- Estimate: 700 - 300 = 400
6. 752 - 542
- 752 → tens digit 5 → round up → 800
- 542 → tens digit 4 → round down → 500
- Estimate: 800 - 500 = 300
7. 561 - 338
- 561 → tens digit 6 → round up → 600
- 338 → tens digit 3 → round down → 300
- Estimate: 600 - 300 = 300
8. 676 - 313
- 676 → tens digit 7 → round up → 700
- 313 → tens digit 1 → round down → 300
- Estimate: 700 - 300 = 400
9. 576 - 523
- 576 → tens digit 7 → round up → 600
- 523 → tens digit 2 → round down → 500
- Estimate: 600 - 500 = 100
---
Part 2: Round to the nearest thousand
Rule: Look at the hundreds digit. If it’s 5 or more, round up. If less than 5, round down.
1. 7736 - 5642
- 7736 → hundreds digit 7 → round up → 8000
- 5642 → hundreds digit 6 → round up → 6000
- Estimate: 8000 - 6000 = 2000
2. 6523 - 3412
- 6523 → hundreds digit 5 → round up → 7000
- 3412 → hundreds digit 4 → round down → 3000
- Estimate: 7000 - 3000 = 4000
3. 8734 - 4512
- 8734 → hundreds digit 7 → round up → 9000
- 4512 → hundreds digit 5 → round up → 5000
- Estimate: 9000 - 5000 = 4000
4. 5429 - 3123
- 5429 → hundreds digit 4 → round down → 5000
- 3123 → hundreds digit 1 → round down → 3000
- Estimate: 5000 - 3000 = 2000
5. 4736 - 2338
- 4736 → hundreds digit 7 → round up → 5000
- 2338 → hundreds digit 3 → round down → 2000
- Estimate: 5000 - 2000 = 3000
6. 7612 - 3241
- 7612 → hundreds digit 6 → round up → 8000
- 3241 → hundreds digit 2 → round down → 3000
- Estimate: 8000 - 3000 = 5000
7. 8712 - 6532
- 8712 → hundreds digit 7 → round up → 9000
- 6532 → hundreds digit 5 → round up → 7000
- Estimate: 9000 - 7000 = 2000
8. 5332 - 3412
- 5332 → hundreds digit 3 → round down → 5000
- 3412 → hundreds digit 4 → round down → 3000
- Estimate: 5000 - 3000 = 2000
9. 6532 - 2312
- 6532 → hundreds digit 5 → round up → 7000
- 2312 → hundreds digit 3 → round down → 2000
- Estimate: 7000 - 2000 = 5000
---
Final Answer:
Rounding to nearest hundred:
476 - 238 → 500 - 200 = 300
276 - 138 → 300 - 100 = 200
342 - 145 → 300 - 100 = 200
861 - 345 → 900 - 300 = 600
676 - 312 → 700 - 300 = 400
752 - 542 → 800 - 500 = 300
561 - 338 → 600 - 300 = 300
676 - 313 → 700 - 300 = 400
576 - 523 → 600 - 500 = 100
Rounding to nearest thousand:
7736 - 5642 → 8000 - 6000 = 2000
6523 - 3412 → 7000 - 3000 = 4000
8734 - 4512 → 9000 - 5000 = 4000
5429 - 3123 → 5000 - 3000 = 2000
4736 - 2338 → 5000 - 2000 = 3000
7612 - 3241 → 8000 - 3000 = 5000
8712 - 6532 → 9000 - 7000 = 2000
5332 - 3412 → 5000 - 3000 = 2000
6532 - 2312 → 7000 - 2000 = 5000
We are asked to estimate the difference by rounding numbers — first to the nearest hundred, then to the nearest thousand.
---
Part 1: Round to the nearest hundred
Rule: Look at the tens digit. If it’s 5 or more, round up. If less than 5, round down.
1. 476 - 238
- 476 → tens digit is 7 → round up → 500
- 238 → tens digit is 3 → round down → 200
- Estimate: 500 - 200 = 300
2. 276 - 138
- 276 → tens digit 7 → round up → 300
- 138 → tens digit 3 → round down → 100
- Estimate: 300 - 100 = 200
3. 342 - 145
- 342 → tens digit 4 → round down → 300
- 145 → tens digit 4 → round down → 100
- Estimate: 300 - 100 = 200
4. 861 - 345
- 861 → tens digit 6 → round up → 900
- 345 → tens digit 4 → round down → 300
- Estimate: 900 - 300 = 600
5. 676 - 312
- 676 → tens digit 7 → round up → 700
- 312 → tens digit 1 → round down → 300
- Estimate: 700 - 300 = 400
6. 752 - 542
- 752 → tens digit 5 → round up → 800
- 542 → tens digit 4 → round down → 500
- Estimate: 800 - 500 = 300
7. 561 - 338
- 561 → tens digit 6 → round up → 600
- 338 → tens digit 3 → round down → 300
- Estimate: 600 - 300 = 300
8. 676 - 313
- 676 → tens digit 7 → round up → 700
- 313 → tens digit 1 → round down → 300
- Estimate: 700 - 300 = 400
9. 576 - 523
- 576 → tens digit 7 → round up → 600
- 523 → tens digit 2 → round down → 500
- Estimate: 600 - 500 = 100
---
Part 2: Round to the nearest thousand
Rule: Look at the hundreds digit. If it’s 5 or more, round up. If less than 5, round down.
1. 7736 - 5642
- 7736 → hundreds digit 7 → round up → 8000
- 5642 → hundreds digit 6 → round up → 6000
- Estimate: 8000 - 6000 = 2000
2. 6523 - 3412
- 6523 → hundreds digit 5 → round up → 7000
- 3412 → hundreds digit 4 → round down → 3000
- Estimate: 7000 - 3000 = 4000
3. 8734 - 4512
- 8734 → hundreds digit 7 → round up → 9000
- 4512 → hundreds digit 5 → round up → 5000
- Estimate: 9000 - 5000 = 4000
4. 5429 - 3123
- 5429 → hundreds digit 4 → round down → 5000
- 3123 → hundreds digit 1 → round down → 3000
- Estimate: 5000 - 3000 = 2000
5. 4736 - 2338
- 4736 → hundreds digit 7 → round up → 5000
- 2338 → hundreds digit 3 → round down → 2000
- Estimate: 5000 - 2000 = 3000
6. 7612 - 3241
- 7612 → hundreds digit 6 → round up → 8000
- 3241 → hundreds digit 2 → round down → 3000
- Estimate: 8000 - 3000 = 5000
7. 8712 - 6532
- 8712 → hundreds digit 7 → round up → 9000
- 6532 → hundreds digit 5 → round up → 7000
- Estimate: 9000 - 7000 = 2000
8. 5332 - 3412
- 5332 → hundreds digit 3 → round down → 5000
- 3412 → hundreds digit 4 → round down → 3000
- Estimate: 5000 - 3000 = 2000
9. 6532 - 2312
- 6532 → hundreds digit 5 → round up → 7000
- 2312 → hundreds digit 3 → round down → 2000
- Estimate: 7000 - 2000 = 5000
---
Final Answer:
Rounding to nearest hundred:
476 - 238 → 500 - 200 = 300
276 - 138 → 300 - 100 = 200
342 - 145 → 300 - 100 = 200
861 - 345 → 900 - 300 = 600
676 - 312 → 700 - 300 = 400
752 - 542 → 800 - 500 = 300
561 - 338 → 600 - 300 = 300
676 - 313 → 700 - 300 = 400
576 - 523 → 600 - 500 = 100
Rounding to nearest thousand:
7736 - 5642 → 8000 - 6000 = 2000
6523 - 3412 → 7000 - 3000 = 4000
8734 - 4512 → 9000 - 5000 = 4000
5429 - 3123 → 5000 - 3000 = 2000
4736 - 2338 → 5000 - 2000 = 3000
7612 - 3241 → 8000 - 3000 = 5000
8712 - 6532 → 9000 - 7000 = 2000
5332 - 3412 → 5000 - 3000 = 2000
6532 - 2312 → 7000 - 2000 = 5000
Parent Tip: Review the logic above to help your child master the concept of estimating sums and differences worksheet.
