FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -Probably of Babylonian origin, an abacus is a calculating instrument that uses beads that slide along a series of wires or rods set in a frame to represent the decimal places. It is the ancestor of the modern digital calculator.

Detailed explanation-2: -The abacus (plural abaci or abacuses), also called a counting frame, is a calculating tool which has been used since ancient times.

Detailed explanation-3: -A horizontal crossbar perpendicular to the rods separates the abacus into two unequal parts. The beads above the crossbar are known as heaven beads or upper beads, and those below the crossbar are called earth beads or lower beads.

Detailed explanation-4: -The abacus is a device, usually of wood (romans made them out of metal and they are made of plastic in modern times), having a frame that holds rods with freely-sliding beads mounted on them.

Detailed explanation-5: -The abacus is divided into the upper and the lower part by a horizontal bar called the Beam. The beads in the lower part are the Lower Beads or the Earth Beads. The beads in the upper part are the Upper Beads or the Heaven Beads.