### Prefixes

The following table shows the commonly used prefixes associated with the powers of 10.

Measurement prefixes
Prefix Power Symbol Prefix Power Symbol
kilo $$10^3$$ k milli $$10^{-3}$$ m
mega $$10^6$$ M micro $$10^{-6}$$ $$\mu$$
giga $$10^9$$ G nano $$10^{-9}$$ n
tera $$10^{12}$$ T pico $$10^{-12}$$ p
peta $$10^{15}$$ P femto $$10^{-15}$$ f

#### Examples

• The Hume dam has a capacity of 3 005 266 megalitres which is written 3 005 266 ML.
• Human hair ranges from 18 micrometres (18 $$\mu\text{m}$$) to 180 micrometres (180 $$\mu\text{m}$$).
• The sub-atomic particle, the proton, is estimated to have a radius of 0.8768 femometres (0.8768 fm).
• The distance that light travels in a week is 146 Tm.
• The angstrom (Å) is used in the natural sciences to express the size of atoms, the lengths of chemical bonds and the wavelengths of electronic radiation. 1 angstrom = $$10^{-1}$$ nanometres = $$10^{-10}$$ metres.