abacus

abacus, calculating device, probably of Babylonian origin, that was long important in commerce. It is the ancestor of the modern calculating machine and computer. The earliest “abacus” likely was a board or slab on which a Babylonian spread sand in order to trace letters for general writing purposes. The word abacus is probably derived, through its Greek form abakos, from a Semitic word such as the Hebrew ibeq (“to wipe the dust”; noun abaq, “dust”)....