Estimation
On this page children practise estimating the result of a calculation by rounding first, and judging whether an answer is reasonable. Start with the short method and the examples, then use the online practice or print a worksheet with answers.
How to solve this
- Estimation means finding an approximate answer quickly by rounding the numbers before calculating.
- Round each number to its leading digit (nearest ten or hundred), compute, and use this as your sanity check.
- Check: your exact answer should be within a small range of your estimate — if not, recheck the exact calculation.
Examples
Estimate: 387 + 412 ≈ ?
800
Estimate: 593 − 198 ≈ ?
400
Practice problems with answers
Solve these problems on paper or out loud, then check the answer key. The online practice and the printable worksheet give a new set every time.
- Estimate: 590 − 348 ≈ ___
- Estimate: 442 + 410 ≈ ___
- Estimate: 204 + 142 ≈ ___
- Estimate: 353 − 193 ≈ ___
- Estimate: 222 + 218 ≈ ___
- Estimate: 581 − 365 ≈ ___
- Estimate: 741 − 600 ≈ ___
- Estimate: 463 + 240 ≈ ___
Show answers
- ≈300
- ≈800
- ≈300
- ≈200
- ≈400
- ≈200
- ≈100
- ≈700