# SI Multiplier Prefixes

An **SI prefix** is a symbol attached to an SI unit that serves as short-hand for scientific notation. The **SI multiplier prefixes** represent quantities that are orders of magnitude larger than the base unit. They are used in unison with SI divisor prefixes.

The most important of these prefixes will be familiar to anyone who has been exposed to computer memory (bytes, kilobytes, megabytes, gigabytes, terabytes, etc.) Generally, a unique prefix is given to each power of 1,000, with exceptions for the quantities less than 1,000.

Prefix | $10 ^ n$ | Symbol |

yotta- | $10 ^ {24}$ | Y |

zetta- | $10 ^ {21}$ | Z |

exa- | $10 ^ {18}$ | E |

peta- | $10 ^ {15}$ | P |

tera- | $10 ^ {12}$ | T |

giga- | $10^ 9$ | G |

mega- | $10 ^ 6$ | M |

kilo- | $10^3$ | k |

hecto- | $10^2$ | h |

deca- | $10^1$ | da |

The prefixes save time and space when working through problems, as a single letter (or two, in the case of deca-) is much shorter than $\text{"times }10^n\text{."}$

How many grams are in $100 \text{ hg}$?

$100 \text{ hg} = 100\times 10^2 \text{ g} = 10,000 \text{ g}$

**Cite as:**SI Multiplier Prefixes.

*Brilliant.org*. Retrieved from https://brilliant.org/wiki/si-multiplier-prefixes/