Curt Herzstark is recognized with developing a calculator that could be held in one hand in the year 1948. It had many larger, bulkier predecessors.
1888
what year was the graphing calculator invented
You answer internet
1568
1568
The back hand spring was usually invented in the 1960's if u ask me
the year 1858
1991
Hand sanitizer was invented in 1966 by Lupe Hernandez, a registered nurse in California. She wanted to find a faster way to disinfect her hands in between patient visits.
1990
1888