An illustration of Pascal's mechanical calculator, circa 1642, also known as a pascaline. Blaise Pascal (1623 - 1662) was a French mathematician, physicist, philosopher, writer and inventor of the mechanical calculating machine. The pascaline used cogged wheels to perform additions and subtractions. It is thought that about 70 of these machines were constructed. Pascal, a polymath, also made contributions to geometry, hydrostatics, and, with Fermat, founded probability theory. After nearly dying in 1654, Pascal abandoned mathematics in favor of philosophy.