The Abacus and the Numeral Frame
The Chinese Abacus

The counters used by European merchants moved along lines drawn on a surface. In the Chinese, Japanese, or Russian abacus, counters move along rods or wires held in a rectangular frame. Scholars disagree about how long such instruments have been made and about whether the Asian abacus was influenced by the counters of the Greeks. Both Chinese and Japanese abaci have a crossbar.Counters above the crossbar have a value of five, while those below represent one. In the Chinese abacus (suan-pan), there are two beads above the crossbar and five below.