The Soroban is an abacus developed in Japan. It is derived from China and imported to Japan in 1600.
The soroban is composed of an odd number of columns or rods, each having beads: one bead having a value of 5, called go-dama and 4 beads each having a value of 1, called ichi-dama. Each set of beads of each rod is divided by a bar known as a reckoning bar.
The beads and rods are made of a variety of different materials. Most soroban are made of wood and have wood, metal, ratten or bamboo rods for the beads to slide on. The beads themselves are usually biconal (shaped likea double-cone)
