SI prefix reference
- 1 km = 10³ m, 1 Mm = 10⁶ m, 1 Gm = 10⁹ m
- 1 mm = 10⁻³ m, 1 µm = 10⁻⁶ m, 1 nm = 10⁻⁹ m
- 1 kg = 1000 g, 1 mg = 0.001 g, 1 µg = 10⁻⁶ g
FAQ
Why use prefixes instead of scientific notation?
SI prefixes are easier to read for everyday quantities — "5 km" is clearer than "5 × 10³ m". Scientific notation is preferred for very large or very small extremes, where prefixes get unwieldy.