Engraving of a Rechentisch (Counting Board)

This image of an engraving depicts a man using a rechentisch, or counting board, the earliest known counting device and a precursor the abacus. The earliest known counting board is the Salamis Tablet, dating from 300 BCE, but may have been used more for gaming than for calculating. There are few surviving counting boards due to the materials used for construction and their use in daily life. This engraving depicts the man using the board for calculating, demonstrated by the bag full of counters and the markings on the board. This engraving likely comes from Strasbourg, which is now in France. 

This source is part of the History of Pre-Modern Math Methods module.