Events Tagged: "abacus"

Abacus developed in Mesopotamia - first known calculating device using beads on rods for arithmetic

Chinese develop suanpan abacus - more advanced with 2 beads above bar and 5 below, enables hexadecimal calculation

Romans develop portable hand abacus - bronze tablet with grooves and counters for merchants and engineers

Japanese soroban abacus refined - 1 bead above, 4 below bar, still used today in Japanese schools