History of the abacus

As the revolution in computing advances, it is appropriate to step back and look at the earliest practical aid to computation?? abacus. Its formal western origins lie with the Greeks and the expansion of trade in the seventh century BC, and its design and application showed remarkably little change over the following two thousand years. A measure of the usefulness of the abacus is seen by the fact that it survived the advent of algorism by some six centuries but its major significance for western culture lies in its perfect and seminal representation of the decimal system.