Adam Ries (1492 or 1493 – 30 March 1559) was a German mathematician. He is also known by the name Adam Riese. He is known as the "father of modern calculating" because of his decisive contribution to the recognition that Roman numerals are unpractical and to their replacement by the considerably more practical Arabic numerals.
HistoryLayer draws the world as it was in any year from 123,000 BCE to
2026. Move the slider and the borders redraw for that year; the map
carries 23,890 events, 12,790 people, 837 wars and 13,183 cities, each
one readable in place. Signing in is optional and lets you keep what
you find.