| Noun | 1. | calculating machine - a small machine that is used for mathematical calculationsabacus - a calculator that performs arithmetic functions by manually sliding counters on rods or in grooves adder - a machine that adds numbers hand calculator, pocket calculator - a calculator small enough to hold in the hand or carry in a pocket machine - any mechanical or electrical device that transmits or modifies energy to perform or assist in the performance of human tasks Napier's bones, Napier's rods - a set of graduated rods formerly used to do multiplication and division by a method invented by John Napier quipu - calculator consisting of a cord with attached cords; used by ancient Peruvians for calculating and keeping records subtracter - a machine that subtracts numbers |