Part 0 · 1 chapters · ~8 min

Calculation Before Computers

Counting and tally marks, the abacus, Napier's logarithms and slide rules, mechanical calculators (Pascal, Leibniz), Leibniz and binary, human "computers" (people whose job was calculating), Jacquard's punched-card loom, and Hollerith's tabulators and the 1890 census.

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People, gears and cards

Until the mid-20th century, a "computer" was a person: teams of human computers, often women, calculated astronomical tables, artillery trajectories and later NASA flight paths (the story told in Margot Lee Shetterly's Hidden Figures, 2016). Mechanical aids sped them up; punched cards let machines store and sort data, an idea that survived into the 1970s.

Martin Campbell-Kelly, William Aspray and others, Computer: A History of the Information Machine (3rd ed., 2014); David Alan Grier, When Computers Were Human (2005); Margot Lee Shetterly, Hidden Figures (2016).

CALCULATION BEFORE COMPUTERS
tools that made arithmetic faster
c. 2400 BCEcounting boards(Mesopotamia)c. 1200sChinese suanpan abacus
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counting aids
Counting boards and the abacus made arithmetic faster for merchants and officials for thousands of years; skilled abacus users still compete with calculators.
abacus and counting boardsstill in use