abacus

abacus   Mathematics. a counting frame used to aid in arithmetic computation by manually sliding markers on rods or wires or in grooves. Two forms are especially common, both with markers divided into two sections: the biquinary Chinese hsuan-pan, in which each wire has two markers in the upper section and five in the lower, and the Japanese soroban, in which the upper section has one marker per wire and the lower has four per wire.  Architecture. a slab that forms the uppermost section or division of the capital of a column