abacus |
a device used to make arithmetic calculations, consisting of a frame with parallel rods or grooves that hold movable counters such as beads. |

accumulator |
a register or electrical circuit for storing numbers and performing one or more arithmetic or logical operations on them, as in a calculator or computer. [1/3 definitions] |

arithmetic |
a book on the subject of arithmetic. [2/3 definitions] |

arithmetician |
one skilled in arithmetic. |

average |
the arithmetic mean gained by adding two or more quantities and then dividing by the total number of quantities. [4/9 definitions] |

average out |
to amount to an average according to arithmetic calculation (usu. fol. by "to"). [1/2 definitions] |

avg. |
abbreviation of "average," the arithmetic mean gained by adding two or more quantities and then dividing by the total number of quantities. |

by |
in arithmetic, for multiplication of one number times another. [2/16 definitions] |

centroid |
the arithmetic mean of all points that form the boundary of a two- or three-dimensional object. |

cipher |
to solve (a problem) by using arithmetic; calculate. [1/7 definitions] |

denominator |
in arithmetic, the number in a fraction that is below the division line, indicating the number of equal parts into which the number above is to be divided; divisor. |

figure |
(pl.) arithmetic. [1/16 definitions] |

mean deviation |
a measure of variability, esp. in a statistical distribution, that is equal to the average of the absolute values of a set of deviations from the arithmetic mean or some other specified value. |

mean distance |
the arithmetic average of the greatest and least distances of a planet from the sun, used to describe the size of the planet's orbit. |

minuend |
in arithmetic, a number from which another number is subtracted. (Cf. subtrahend.) |

multiplication |
an arithmetic process by which one number is added to itself as many times as the other number indicates. [1/2 definitions] |

multiply^{1} |
to find the product of (two numbers) by the arithmetic process of multiplication. [2/5 definitions] |

number |
(pl.) arithmetic. [1/18 definitions] |

quadrivium |
in medieval universities, the higher section of the liberal arts, comprising arithmetic, geometry, astronomy, and music. (Cf. trivium.) |

quotient |
that number which is obtained as the result of an arithmetic division. |

root mean square |
the square root of the arithmetic mean of the squares in a given set of numbers. |