Topic summary
Electronic calculator
Extracted from the Wikipedia article Calculator.
Precursors to the electronic calculator
The first known tools used to aid arithmetic calculations were: bones (used to tally items), pebbles, counting boards, and the abacus, which have been used by Sumerians and Egyptians before 2000 BC. Except for the Antikythera mechanism (an "out of the time" astronomical device), development of computing tools arrived near the start of the 17th century: the geometric-military compass (by Galileo), logarithms and Napier bones (by Napier), and the slide rule (by Edmund Gunter).