Any device built to perform or help perform computations, such as the abacus, slide rule, or computer.
The earliest known example is the abacus. Mechanical devices with sliding scales (similar to the slide rule) date from ancient Greece. In 1642, French mathematician Blaise Pascal built a mechanical adding machine and, in 1671, German mathematician Gottfried Leibniz produced a machine to carry out multiplication. The first mechanical computer, the analytical engine, was designed by British mathematician Charles Babbage 1835. For the subsequent history of computing, see computer.