Gottfried Wilhelm Leibniz spent over twenty years perfecting this machine, the first calculator capable of all four arithmetic operations. Its key innovation was the "stepped drum" (Leibniz wheel) -- a cylinder with nine teeth of increasing length. As the drum rotates, a smaller counting wheel engages with 0-9 teeth depending on its position along the drum, encoding multiplication in a single turn. The carriage shifts to handle different decimal places, enabling multiplication and division through repeated addition and subtraction.
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