Roman abacus
= Roman abacus
{wiki=Roman_abacus}
The Roman abacus, also known as the "Calculus," is a counting tool used in ancient Rome for performing arithmetic calculations. It typically consists of a flat surface with grooves or lines, and it can be equipped with movable beads or pebbles that represent numerical values. The structure of a Roman abacus could vary, but it generally featured a rectangular frame with horizontal and vertical lines where counters could be placed.