quipu

A cord about 2 feet in length, tightly spun from variously colored threads, and having a number of smaller threads attached to it in the form of a fringe: used among the ancient Peruvians and elsewhere for recording events, etc.

A contrivance employed by the ancient Peruvians, Mexicans, etc., as a substitute for writing and figures, consisting of a main cord, from which hung at certain distances smaller cords of various colors, each having a special meaning, as silver, gold, corn, soldiers. etc. Single, double, and triple knots were tied in the smaller cords, representing definite numbers. It was chiefly used for arithmetical purposes, and to register important facts and events.

A recording device, used by the Incas, consisting of intricate knotted cords.

calculator consisting of a cord with attached cords; used by ancient Peruvians for calculating and keeping records