Definition
- All non-zero digits are always significant.
- Any zeros between two non-zero digits are significant.
- Leading zeros (zeros to the left of the first nonzero digit) are insignificant.
- Trailing zeros (zeros to the right of the last non-zero digit):
- Significant if the number contains a decimal point.
- Insignificant otherwise.
Examples
- 4050: Three
- 0.00406: Three
- 6.200: Four
- 4000: One
Calculation Rules
- Addition & Subtraction: Round to the same decimal place as the number with the fewest decimal places.
- Multiplication & Division: Same number of significant figures as the number with the fewest significant figures.
- Square Roots: Original number has n significant figures, result has n+1 significant figures.