Prefixes to Power of Ten
A mechanism through which numbers are expressed in powers of ten that are given a proper name is called a prefix. Prefixes make standard form or scientific notation easier. Large numbers are simply written in more convenient prefixes with units. For example, the thickness of a paper can be written conveniently in smaller units of millimetre instead of metre.
| Decimal Multiplier | Prefix | Symbol |
|---|---|---|
| 10^18 | Exa | E |
| 10^15 | Peta | P |
| 10^12 | Tera | T |
| 10^9 | Giga | G |
| 10^6 | Mega | M |
| 10^3 | Kilo | k |
| 10^2 | Hecto | h |
| 10^1 | Deca | da |
| 10^-1 | Deci | d |
| 10^-2 | Centi | c |
| 10^-3 | Milli | m |
| 10^-6 | Micro | μ |
| 10^-9 | Nano | n |
| 10^-12 | Pico | p |
| 10^-15 | Femto | f |
| 10^-18 | Atto | a |
Examples
- The number of seconds in a day is: 86,400 seconds = 8.64 x 10^4 s = 86.4 ks.
- The distance to the nearest star, Alpha Centauri, is: 4.132 x 10^16 m = 41.32 Pm.
- The thickness of the page of this book is about: 4.0 x 10^-4 m = 40 x 10^-3 m = 40 mm.
- The mass of a grain of salt is: 1.0 x 10^-4 g = 100 x 10^-6 g = 100 mg.