On September 20, 1996, Hungarian mathematician Paul Erdös passed away. He published more scientific papers than any other mathematician in history, with hundreds of collaborators.
On October 23, 1635, German astronomer and mathematician Wilhelm Schickard, who constructued the very first mechanical calculator, passed away. His famous calculator was able to perform additions and subtractions. For more complicated operations, it provided so-called Napier bones, named after the Scottish mathematician John Napier, who came up with the idea of logarithms. Although it is widely believed that the first mechanical calculating device was created by the French mathematician Blaise Pascal in 1642. However, that distinction actually belongs to Wilhelm Schickard.