This post is about pre-fixes, those short letter combinations that appear in front of other (math) words.

Prefix | Meaning | Example |

bi- | two | bicycle |

centi- | one hundred | centimeter, century |

dec- | ten | decade |

deci- | one-tenth | decimeter |

equi- | equal ("in the middle") | equidistant, equiangular |

femto- | 10⁻¹⁵ or 0.000000000000001 | femtocell phone transmitter (Danish femten 15) |

giga- | 10⁹ or 1,000,000,000 | gigabytes |

hemi- | half a sphere | hemisphere, Chrysler HEMI |

hex- | six | hexagon, hex wrench |

kilo- | 10³ or 1,000 | kilometer |

mega- | 10⁶ or 1,000,000 ("big") | megabytes, "it's a mega-project" |

That's enough - I think you get the idea. Of course there are many more obscure prefixes, but these are commonly used in the math world, and it's essential to know most of them. Especially if you are taking at test and the question reads:

**Select One: Is a quadrilateral considered to be (1) a regular polygon or (2) a pentathlon?**

You might have read about OVERACHIEVING, PRECOCIOUS PRODIGIES, those brilliant folk whose math ability TRANSCENDS that of UNDERACHIEVERS. Notice all the prefixes?

**Un**like the

**pre**vious list of

**pre**fixes, the following group deals with position and order rather than

**num**erical or

**calc**ulation terms. Nevertheless, these are commonly used mathematics

**pre**fixes too.

Prefix | Meaning | Example |

circum- | around | circumference, circumnavigate (the middle) |

inter- | between | intersection, international |

over- | above, upper, excessive | overconfident |

pre- | ahead, before in line, first in order | prelude, precocious |

pro- | favoring, motion forward, before its time | propulsion, prodigy |

trans- | across, beyond | transatlantic, translate, transcend |

under- | below, behind | underachievers, underarm |