# slide rule

slide rule a once-common manual device like a ruler but with a central sliding piece, both parts being marked with various number scales: used to find square roots, logarithms, quotients, etc.

## slide rule

noun

A device consisting of two logarithmically scaled rules mounted to slide along each other so that multiplication, division, and other more complex computations are reduced to the mechanical equivalent of addition or subtraction.

## slide-rule

Noun

(*plural* slide rules)

- An analog calculator consisting of three interlocking strips marked with logarithmic scales, such that multiplication, division etc. can be performed by the equivalent of addition and subtraction.

## slide rule - Computer Definition

An early computing device invented by Reverend William Oughtred in London in the 17th century. Primarily for multiplication and division, the slide rule has two stationary sets and one sliding set of numbers in the center. To multiply, numbers are added; to divide, numbers are subtracted. Subsequent slide rules added scales for trigonometric, powers and root computations.