††††An abacus is a simple kind of calculator used for addition and subtraction.
A early form of abacus used beads strung on wires, and was made by the Chinese around the year 3000 BC. However, it is likely that the modern abacus did not appear until at least the first century, probably also in China.
By the year 500 AD the invention had spread to Europe. Aids to arithmetic have been developed ever since: the modern calculator is now an everyday object, but the abacus is still used in the East today.
