a thin, flat calculating device consisting of a fixed outer piece and a movable middle piece. Both pieces are graduated in such a way (as, by a logarithmic scale) that multiplication, division, and other mathematical functions of an input variable may be rapidly determined by movement of the middle pieces to a location on one scale corresponding to the input value, and reading off the result on another scale. A movable window with a hairline assists in alignment of the scales. This device has been largely superseded by the electronic calculator, which has a greater precision than the slide rule. Also called colloquially slipstick.

While calculators were available by this time (the first Bomars and HPs had just come out), they could only be afforded by the richest of students. The rest of us had slide rules. I finally built a Sinclair (yes, that Sinclair) scientific calculator from a kit, it displayed all results in scientific notation, and had 4 1/2 digits of precision.

analog computer consisting of a handheld instrument used for rapid calculations; have been replaced by pocket calculators