Scientific Notation and Significant Figures
Convert any number to m * 10^n form; count significant figures from the input string.
Example
You enter
- Number (decimal or scientific) 0.00347
You get
- Mantissa (1 <= |m| < 10) 3.47
- Exponent (n) -3
- Significant figures (from input string) 3
Checked against published worked examples from: NIST SP 811 (Guide for the Use of the International System of Units).
Details, formula, and sources
Formula or tableScientific notation: any nonzero number x = sign(x) * m * 10^n where 1 <= m < 10 and n = floor(log10(|x|)). Significant figures are read from the input string: leading zeros are not significant; embedded zeros and trailing zeros after a decimal point are significant.
Source and editionStandard scientific notation. Significant-figure conventions per the SI / NIST guidance for measurement reporting.
Free accessPublic reference; NIST SP 811 (Guide for the Use of the International System of Units) covers significant-figure conventions.
What governsEstimate only. Readability formulas and similar metrics are derived from a representative population and have known edge-case noise. The classroom teacher governs final text selection, grade placement, and assessment decisions.
API field namesvalue, mantissa, exponent, sig_figs
- Zero handling 0 returns mantissa 0 and exponent 0 with sig figs = 1convention
- Input form decimal or scientific notation accepted; the sig-fig count uses the raw input string before normalizationconvention