Abacus

Also called a counting frame, it’s a series of wires and beads arranged in rows that allows the user to perform mathematic calculations, no electronic calculator required.

The abacus has been used for centuries by merchants, clerks, students and accountants to get the job of crunching numbers done. In fact, the thing has been around so long that even the smartest historians can’t agree who invented it.

What we do know is that it was used by the Mesopotamians, Egyptians, Persians, Chinese, Greeks, Romans and more, with the earliest documented use dating back some 4,000 years ago.  

Some versions of the abacus have ten beads on each row, others five, but the general function of each model is the same.