The abacus was probably invented by the Babylonians.
It was refined and used by the Romans, Chinese, Arabs, Europeans, and Asians as late as the seventeenth century.
It is still used, in various forms, in the Middle East and Japan.
The abacus was probably invented by the Babylonians.
It was refined and used by the Romans, Chinese, Arabs, Europeans, and Asians as late as the seventeenth century.
It is still used, in various forms, in the Middle East and Japan.