計けい算さん尺じゃく

noun

slide rule

A mechanical analog computing device used for multiplication, division, and other mathematical operations before electronic calculators became common.

• 祖そ父ふは計けい算さん尺じゃくを使つかって設せっ計けい図ずを描かいていた。

  My grandfather used a slide rule to draw blueprints.