SAIF UR REHMAN 

The abacus (plural abaci or abacuses), also called a counting frame, is a calculating tool used primarily in parts of Asia for performing arithmetic processes. Today, abaci are often constructed as a bamboo frame with beads sliding on wires, but originally they were beans or stones moved in grooves in sand or on tablets of wood, stone, or metal. The abacus 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. The user of an abacus is called an abacist.^[2]
he use of the word abacus dates before 1387 AD, when a Middle English work borrowed the word from Latin to describe a sandboard abacus. The Latin word came from Greek ἄβαξ abax "board strewn with sand or dust used for drawing geometric figures or calculating" (the exact shape of the Latin perhaps reflects the genitive form of the Greek word, ἄβακoς abakos). Greek ἄβαξ itself is probably a borrowing of a Northwest Semitic, perhaps Phoenician, word akin to Hebrew ʾābāq (אבק), "dust" (since dust strewn on wooden boards to draw figures in).^[3] The preferred plural of abacus is a subject of disagreement, with both abacuses^[4] and abaci^[5] in use.