In 3000 BC Mesopotamians introduced this and it means calculating board or frame. It is considered as the first computer for basic arithmetical calculations and consists of beads on movable rods divided into two parts.
The Chinese improved the Abacus with seven beads on each wire. A horizontal divider separates the top two beads from the bottom five. The top two beads have a place value of 5 and the below five beads. The beads which are pushed against the horizontal bar represent the number.