Who invented the first practical mechanical calculator, the Pascaline, in 1642?

Blaise Pascal invented the first practical mechanical calculator, the Pascaline, in 1642.

Pascal built the machine in France while still a teenager. His father worked as a tax commissioner, and the repetitive arithmetic involved in calculating taxes inspired Pascal to create a device that could perform addition and subtraction mechanically.

The Pascaline used numbered dials and geared wheels. A carrying mechanism allowed a full turn of one wheel to advance the next wheel, making multi-digit calculations possible. The machine was difficult and expensive to manufacture, so it never became a mass-market product.

The Pascaline is often mentioned alongside later calculating machines. Gottfried Wilhelm Leibniz developed a calculator capable of multiplication and division, while Charles Babbage designed much more advanced programmable mechanical engines in the nineteenth century. Pascal’s device nevertheless established an important foundation for mechanical calculation.