Oriental Calculator that adds, subtracts, multiplies and divides. Abacus comes with instruction book. Parts and appellation Abacus is a flat, oblong calculating instrument with a nuber of counting beads that side back and forth along rods or in grooves. A crosswise bar, divides Abacus into two parts : the upper part that contains 2 rows of the 5-value counting beads and the lower containing 5 rows of the 1-value counting beads. Keep in mind that every single bead about the crosswise bar has the value of "five" and that the beads below bar have the value of "one" respectively. The columns. towards the left always have higher values than those towards the right. Each column has two 5-value counting beads above the bar and five 1-value beads below it, making the value of fifteen altogether. On the crosswise bar are several dots calibrated on every forth column and they are to be used to indicate the unit point of numbers or a decimal point. The values of counting beads are determined by their positions. They obtain values when they are slided towards the crosswise bar and lose them when slided away from the bar. The Abacus was invented by the Chinese in 500 BC (some indications will argue on its invention by Babylonians in 300 BC) and was used as one of the most primitive counting devices. The first century sources have also given evidence on abacus being used by Indians with a seperate column that counted digits with "shuyna" (zero). Although, the history still searches for facts taht can give a confirmed statement on the invention of abacus.