Jetons were used in the Middle Ages to make calculations in Roman numerals easier. A grid was set out on a table top, with the lines and the spaces between them representing different Roman
numbers. The jetons were then moved about on the grid, like the beads on an abacus. Jetons gradually died out in the 16 -17th centuries as the use of Arabic numbers became more common, but in France they continued to be made for a variety of officials into the 18th century.