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  2. Mechanical calculator - Wikipedia

    en.wikipedia.org/wiki/Mechanical_calculator

    For forty years the arithmometer was the only type of mechanical calculator available for sale until the industrial production of the more successful Odhner Arithmometer in 1890. [ 8 ] The comptometer , introduced in 1887, was the first machine to use a keyboard that consisted of columns of nine keys (from 1 to 9) for each digit.

  3. Comptometer - Wikipedia

    en.wikipedia.org/wiki/Comptometer

    The Comptometer was the first commercially successful key-driven mechanical calculator, patented in the United States by Dorr Felt in 1887.. A key-driven calculator is extremely fast because each key adds or subtracts its value to the accumulator as soon as it is pressed and a skilled operator can enter all of the digits of a number simultaneously, using as many fingers as required, making ...

  4. Stepped reckoner - Wikipedia

    en.wikipedia.org/wiki/Stepped_reckoner

    The stepped reckoner or Leibniz calculator was a mechanical calculator invented by the German mathematician Gottfried Wilhelm Leibniz (started in 1673, when he presented a wooden model to the Royal Society of London [2] and completed in 1694). [1]

  5. Curta - Wikipedia

    en.wikipedia.org/wiki/Curta

    A partially disassembled Curta calculator, showing the digit slides and the stepped drum behind them Curta Type I calculator, top view Curta Type I calculator, bottom view. The Curta is a hand-held mechanical calculator designed by Curt Herzstark. [1] It is known for its extremely compact design: a small cylinder that fits in the palm of the hand.

  6. The Millionaire (calculator) - Wikipedia

    en.wikipedia.org/wiki/The_Millionaire_(calculator)

    In 1881 Chebyshev demonstrated a model of the calculation machine with automatic multiplication but did not take out a patent for it. In 1834 Luigi Torchi of Milan invented a direct multiplication machine. [3] The first patented multiplying machines was due to Edmund Barbour [4] (1872), Ramón Verea [5] (1878) and Léon Bollée (1889). [6]

  7. Brunsviga - Wikipedia

    en.wikipedia.org/wiki/Brunsviga

    Brunsviga 15 Mechanical Calculator Original Odhner-Arithmos-Typ-5. Brunsviga is a calculating machine company whose history goes back to 1892 with devices upgrading from mechanical to electrical thereafter. The firm Grimme & Natalis that manufactured the machines changed their name to Brunsviga Maschinenwerke A.G. in 1927.

  8. Calculator - Wikipedia

    en.wikipedia.org/wiki/Calculator

    The first American-made pocket-sized calculator, the Bowmar 901B (popularly termed The Bowmar Brain), measuring 5.2 by 3.0 by 1.5 inches (132 mm × 76 mm × 38 mm), came out in the Autumn of 1971, with four functions and an eight-digit red LED display, for US$240, while in August 1972 the four-function Sinclair Executive became the first ...

  9. HP-35 - Wikipedia

    en.wikipedia.org/wiki/HP-35

    Was the first scientific calculator to fly in space in 1973. [5] HP-35 calculators were carried on the Skylab 3 and Skylab 4 flights, between July 1973 and February 1974. [6] Is the first pocket calculator with a numeric range that covered 200 decades (more precise 199, ±10 ±99). [5]