calculator

In 1617 Scottish mathematician John Napier published his description of what was arguably the first mechanical calculator - a set of numbered rods, usually made of bone or ivory and therefore known as Napier's bones. Using them, multiplication became merely a process of reading off the appropriate figures and making simple additions.

Pocket-sized electronic computing device for performing numerical calculations. It can add, subtract, multiply, and divide; many calculators also compute squares and roots and have advanced trigonometric and statistical functions. The first electronic calculator was manufactured by the Bell Punch Company in the USA in 1963.