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They have slots with beads in them that can be moved back and forth in the slots similar to counters on a counting board.

A few hand abacuses from that time have been discovered. There is evidence that people were using abacuses in ancient Rome (753 b.c.e.–476, c.e.). It was used by the Babylonians around 300 b.c.e.ĭrawings of people using counting boards have been found dating back to the same time period. It is believed to have been found on Salamis, a Greek island, in 1899, hence the name. The oldest abacus survived to the present day, is the so-called Salamis abacus. The first written information about the abacus that survived to the present, is from the Greek historian Herodotus (480-425 B.C.), who mentioned also, that the ancient Egyptians used an abacus. It is the most primitive form of a calculating device, invented somewhere between 300 and 500 B.C. The exact date of the origin of the abacus is unknown. Download the PDF below to know more about Abacus Basics. It is still used to teach the basics of arithmetic to children. Even today, in the modern world of computers and calculators, it is used by traders, merchants, etc. Merchants commonly used it in Europe and the Arabic world. One could call it a precursor to the modern-day calculator. A horizontal beam separates the structure into two sections, known as the upper deck and the lower deck. The abacus frame has a series of vertical rods on which a number of wooden beads are allowed to slide freely. The abacus is typically constructed of various types of hardwoods and comes in varying sizes. The beads are manipulated with either the index finger or the thumb of one hand.

It can also be used to extract square-roots and cubic roots. The standard abacus can be used to perform addition, subtraction, division, and multiplication. The beads that slide along a series of wires or rods set in a frame to represent the decimal places. Addition and subtraction can easily be performed by moving beads along the wires of the abacus.

Each rod represents a different place value-ones, tens, hundreds, thousands, and so on.Įach bead represents a number, usually 1 or 5, and can be moved along the rods. An abacus or a counting board consists of a wooden frame, rods, and beads.