Names and Symbols of Multipliers The SI (International System of Units) prefixes are used to form decimal multiples and sub multiples of SI units (see left table below). The number names show the corresponding names for each multiplier used in the english language (see right table below). | SI Power Prefixes | Prefix | Symbol | Multiplier | yotta | Y | 1024 | zetta | Z | 1021 | exa | E | 1018 | peta | P | 1015 | tera | T | 1012 | giga | G | 109 | mega | M | 106 | kilo | k | 103 | hecto | h | 102 | deka | da | 101 | deci | d | 10-1 | centi | c | 10-2 | milli | m | 10-3 | micro | µ | 10-6 | nano | n | 10-9 | pico | p | 10-12 | femto | f | 10-15 | atto | a | 10-18 | zepto | z | 10-21 | yocto | y | 10-24 | | | Number Names | USA | UK | Multiplier | septillion | quadrillion | 1024 | sextillion | trilliard | 1021 | quintillion | trillion | 1018 | quadrillion | billiard | 1015 | trillion | billion | 1012 | billion | milliard | 109 | million | million | 106 | thousand | thousand | 103 | hundred | hundred | 102 | ten | ten | 101 | tenth | tenth | 10-1 | hundredth | hundredth | 10-2 | thousandth | thousandth | 10-3 | millionth | millionth | 10-6 | septillionth | milliardth
| 10-9 | sextillionth | billionth
| 10-12 | quadrillionth | billiardth | 10-15 | quintillionth | trillionth | 10-18 | sextillionth | trilliardth | 10-21 | septillionth | quadrillionth | 10-24 | | Scientific Notation and E notation Scientific notation is the way to easily handle very large numbers or very small numbers. E notation is a variation of this and is used in computers, calculators and this web page. Example 1: Ordinary decimal notation: 100 Scientific notation: 1 x 102 or 1.00 x 102 (sometimes zeros are left to define precision) E notation: 1e2 or 1.00e2 (sometimes zeros are also left to define precision) Example 2: Ordinary decimal notation: 1000 Scientific notation: 1 x 103 or 1.000 x 103 (sometimes zeros are left to define precision) E notation: 1e3 or 1.00e3 (sometimes zeros are also left to define precision) Example 3: Ordinary decimal notation: 0.100160 Scientific notation: 1.0061 x 10-1 or 1.00160 x 10-1 (sometimes zeros are left to define precision) E notation: 1.0016e-1 or 1.00160e-1 (sometimes zeros are also left to define precision) Example 4: Ordinary decimal notation: 0.0002 Scientific notation: 2 x 10-4 E notation: 2e-4 |