In 1673 the German mathematician and philosopher Gottfried Wilhelm Lejbnits has created mechanical счетное the device which not only put and subtracted, but also multiplied and divided. Car Lejbnitsa was a bit more difficult than "Paskaliny". Unlike "Paskaliny", numerical wheels, already gear, had a teeth of nine various lengths, and calculations were made at the expense of coupling of wheels. A little modified wheels of Lejbnitsa became a basis mass счетных devices – arithmometers which widely used throughout all XVIII-th century.

Arithmometers have received very wide application. On them carried out even very difficult calculations. For example: calculations of ballistic tables for artillery стрельб. There was also a special trade — the counter — the person working with an arithmometer. But many calculations were made very slowly — even tens counters should work till some weeks and months. The reason is simple — at such calculations the choice of carried out actions and record of results were made by the person, and speed of its work is rather limited. Therefore the person has not stopped on arithmometer creation. Long time people could not think up anything more perfect car Lejbnitsa. But scientists worked, thought out something new, did experiments. Some of them were successful.