How to use this calculator
- Select count, round, arithmetic, or scientific notation mode.
- Enter one value or a comma-separated list.
- Enter the requested significant figures when the mode uses that value.
- Calculate and read any ambiguity warning.
Formula and variables
addition/subtraction: least decimal places; multiplication/division: fewest significant figures
| Symbol | Meaning | Unit |
|---|---|---|
| sf | significant figures | digits |
Worked example
0.00450 has three significant figures; 1500 is ambiguous; 1500. and 1.500e3 explicitly have four.
Interpretation
The parser preserves how a value was written so trailing decimal points and scientific notation remain meaningful.
Common mistakes
- Do not assume trailing whole-number zeros are significant without notation.
- Use comma-separated values only for arithmetic modes.
Frequently asked questions
Are leading zeros significant?
No. Leading zeros locate the decimal point and do not count as significant figures.
Are trailing zeros significant?
Trailing zeros after a decimal point are significant. Trailing whole-number zeros can be ambiguous.
Which rule applies to arithmetic?
Addition and subtraction use decimal places. Multiplication and division use significant figures.
Can I use scientific notation?
Yes. Enter values such as 6.022e23 or 1.0e-6 in a numeric field.
How should I round the result?
Keep extra digits during the calculation. Round the final result to the precision required by your data.