All Excel Math Teacher Editions contain a full glossary of terms, so teachers can help students know the precise definition of the words used in their lessons. You can download a free glossary from our website, in English or Spanish.

Let's take a look at math terms commonly used in ways that distort their "mathematical" meaning.

TERM | Common Usage | Original or Math Meaning |

Angle | to maneuver or scheme | two intersecting rays or line segments |

Average | everyone below me | single number that represents a set of values |

Base | destination for batters | the bottom face or side of a polygon |

Check | inspecting or grading ones work | v-shaped mark on a tally sheet |

Cone | baked shell holding ice cream | 3D figure with 1 circular base and 1 curved surface |

Cylinder | part of revolver that holds bullets | 3D figure with 2 curved edges, 2 circular bases and 1 curved surface |

Decimate | to destroy utterly | take away one-tenth of the whole |

Deductive | subtracting amount of a donation from your taxes | logical reasoning |

Delta | change | rate of change in an option's value with respect to changes in underlying asset price |

Dense | not very smart | very high ratio of mass to volume |

Dividend | money paid me quarterly | a quantity to be split (or divided) by a divisor |

Even | we both get the same amount | an integer evenly divisible by 2 |

Fact Family | relatives speaking truthfully without emotion | related facts involving the same set of numbers |

Flip | politician changing his position on an issue | change in location resulting in a mirror image |

Exponent | little number indicating "squared" or "cubed" | person or a statement that sets something forth |

Infinite | lots of something | an uncountable quantity |

Interest | what banks used to pay on your savings balance | fee charged for use of money |

Intersection | place where many cars stop | a subset of values that are common to all sets being evaluated |

Metrics | units used by other countries to measure things | the distance between members in a set |

Mode | fashion | value in a set that occurs most frequently |

Obtuse | dense, dumb | angle more than 90∘but less than 180∘ |

Odd | strange, weird | number that cannot be divided into two equal groups |

Pentagon | center of the US military industrial complex | five-sided polygon |

Perimeter | line surrounding a military position | distance around a closed figure |

Prime | interest rate banks use to calculate changes to adjustable mortgages | number that has itself and 1 as its only factors |

Quantum | instant jump through space or time | minimum amount of a physical entity involved in an interaction |

Reciprocal | an eye for an eye | two numbers whose product is 1 |

Reflection | face in a mirror | movement of an object across a straight line |

Similar figures | your numbers resemble those of the IRS auditor | 2 figures with the same proportions but not the same size |

Standing order | bank instruction to pay on one's behalf | position of people in line waiting |

Unlikely | hell freezing over | an event with probability less than .5 |

Volume | when you get it you'll be profitable | the cubic units required to fill a 3D figure |

Whole number | price never truthfully disclosed by the purchaser of a car | positive integers; without fractions |

110% | a good effort | impossible |