counting frame การใช้

The abacus, also called a counting frame, is a calculating tool that was in use centuries before the adoption of the written modern numeral system and is still widely used by merchants, traders and clerks in Asia, Africa, and elsewhere; it dates back to at least 2700 2300 BC, when it was used in Sumer.
The "'abacus "'( " plural " "'abaci "'or "'abacuses "'), also called a "'counting frame "', is a calculating tool that was in use in Europe, China and Russia, centuries before the adoption of the written Hindu Arabic numeral system and is still used by merchants, traders and clerks in some parts of Eastern Europe, Russia, China and Africa.