In 1867, Frederick A. P. Barnard, a mathematician and the president of Columbia University in New York, served as a judge at the Exposition universelle, a world’s fair held in Paris. There he saw a ...

The first calculating machines multiplied by repeated addition. To multiple by tens, hundreds, or larger units, one shifted the carriage. From the 1870s, a few inventors proposed machines that could ...

Calculators have evolved over centuries from large computing machines into today’s highly functional, pocket-sized devices capable of performing complex computations, graphing multiple lines at once ...