Anabacus,alsocalledacountingframe,isacalculatingtoolusedprimarilybyAsiansforperformingarithmeticprocesses.Nowadays,abaciareoftenconstructedasawoodenframewithbeadsslidingonwires,butoriginallytheywerebeadsorstonesmovedingroovesinsandorontabletsofwood,stone,ormetal.TheabacuswasinusecenturiesbeforetheadoptionofthewrittenmodernnumeralsystemandisstillwidelyusedbymerchantsandclerksinChina,Japan,Africa,Indiaandelsewhere.
Theuserofanabacusiscalledanabacist;heorsheslidesthebeadsoftheabacusbyhand.