Early Computing

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Earliest computing device

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the abacus

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Abacus invention

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Mesopotamia, 2500 BCE

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Number shown on the abacus?

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1,251

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Device for calculating latitude at sea

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Astrolabe

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Earliest documented use of 'computer'

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1613

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Early definition of "computer"

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A person who did calculations

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Gear-based calculating device by Leibniz (1694)

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The step reckoner

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Step Reckoner usage duration

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Next three centuries

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Computing before the 20th century

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Pre-computed tables

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First military application of computing

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Calculating range tables