slide rule

US /ˈslaɪd ruːl/
UK /ˈslaɪd ruːl/
"slide rule" picture
1.

логарифмическая линейка

a mechanical analog computer, now largely obsolete, used primarily for multiplication and division, and for functions such as roots, logarithms, and trigonometry. It is constructed with a fixed rule and a sliding central piece, both marked with logarithmic scales.

:
Before electronic calculators, engineers relied on a slide rule for complex calculations.
До появления электронных калькуляторов инженеры полагались на логарифмическую линейку для сложных вычислений.
Learning to use a slide rule required understanding logarithms.
Обучение использованию логарифмической линейки требовало понимания логарифмов.