Significant Figures Counter
Count how many significant figures are in a number, and identify which digits are significant. You can use this calculator for significant figures practice: Test your ability to find how many significant figures are in a number.
Enter whole numbers, real numbers, scientific notation or e notation. Example inputs are, 3500, 35.0056, 3.5 x 10^3 and 3.5e3.
How to Identify Significant Figures
Significant figures are the digits of a number that are meaningful in terms of accuracy or precision. They include:
- Any non-zero digit
- Zeros between non-zero digits as in 3003 or 45.60009
- Trailing zeros when a decimal point is present as in 274.3300 or 6750. (zeros are significant because each number has a decimal point)
How to Identify Non-Significant Figures
Digits of a number are not significant when they do not add information regarding the precision of that number. They include:
- Leading zeros as in 0.009 or 0056
- Trailing zeros as in 45000 when no decimal point is present. If an overline is present as in 45000 the overlined zero is significant but the trailing zeros are not significant.
For math with significant figures see our Significant Figures Calculator.
For rounding significant figures see our Rounding Significant Figures Calculator.
Significant Figures Rules
- Non-zero digits are always significant
- Zeros between non-zero digits are always significant
- Leading zeros are never significant
- Trailing zeros are only significant if the number contains a decimal point
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