ClarityHow to use this tool
- Enter decimal number, decimal places, rounding rule.
- Select Calculate to view the result.
- Check the method and assumptions below before using the result.
Input reference and sample values
Use the units and choices shown for each field. Sample values are provided for practice, not as recommendations.
| Input | Format and units | Sample |
|---|---|---|
| Decimal number | Keep the structure and separators shown in the sample. Line breaks are retained in this input. | 123.456 |
| Decimal places | Numeric value. Zero or positive. Maximum: 10. | 2 |
| Rounding rule | Choose Nearest, ties away from zero / Toward positive infinity / Toward negative infinity. | Nearest, ties away from zero |
Result for these sample inputs
123.46
- Decimal places
- 2
- Rounding rule
- nearest
Select Try the example in the form to load these values and calculate them again. This replaces the current form inputs. Compare the result with the method and worked explanation below.
The method, explained
Scale the entered decimal using integer arithmetic, apply the selected rounding rule, and restore the decimal point. Nearest ties move away from zero.
123.456 rounded to two places is 123.46. Under nearest rounding, −1.25 rounded to one place is −1.3.
What to keep in mind
Plain decimal notation only: no thousands separators or scientific notation. At most 60 digits are accepted. Up and down refer to positive and negative infinity, not always away from or toward zero.
Common questions
How is a negative midpoint rounded?
Nearest rounding uses ties away from zero, so −2.5 rounds to −3 at zero decimal places.
Does the calculation use binary floating-point rounding?
No. It operates on the entered decimal digits with integer arithmetic.
Methodology maintained by ClarityKit. How these tools are built and checked.