The abacus is an ancient counting device with movable counters strung on rods and is used to solve arithmetic problems.
Computers and calculators have made the apparatus obsolete.
The word abacus has Semitic roots and came to English through the Greek word abax, meaning “dust” or “sand.”
Before the board with the beads, the ancients sprinkled a flat surface with fine sand for drawing geometric diagrams and solving mathematical problems.
The Sumerian abacus appeared around 2700–2300 BC and was a table of successive columns which delimited the successive orders of magnitude of their sexagesimal number system.
In 1387, written Middle English began referring to the sand-board calculator used by the Arabs by its Latin form abacus.