ABSTRACT
If we search the archeological record, however, we can find direct written evidence and clay artifacts related to the earliest known abaci from Mesopotamia. Sumer, an ancient civilization in the southern part of Mesopotamia, was established by proto-Euphratean people around 5000 BC. The Sumerians at first used tokens (clay objects of various shapes and sizes marked with symbols) to represent items for trade and accounting. By the third millennium BC, these tokens had become “calculi” or clay tokens used for arithmetic calculation, the results of which were written down on clay tablets in the form of abstract numbers. At this time, although the Sumerians had abstract numbers, they did not perform calculations directly with them; numbers were used only for record keeping.
