Have you ever heard of a handheld calculator that was invented by a man named Curt Herzstark while he was a prisoner in a concentration camp? It's called the Curta calculator.
People used to think it was the best portable calculator around until electronic calculators came along in the 1970s.
The Curta calculator looked like a pepper grinder or peppermill because of its shape and how it worked. Some people even called it the "math grenade" because it looked a bit like a hand grenade. How interesting is that?
