What did the first counting board look like?
The earliest counting boards are forever lost because of the perishable materials used in their construction. However, educated guesses can be made about their construction, based on early writings of Plutarch (a priest at the Oracle at Delphi) and others. In outdoor markets of those times, the simplest counting board involved drawing lines in the sand with ones fingers or with a stylus, and placing pebbles between those lines as place-holders representing numbers (the spaces between 2 lines would represent the units 10s, 100s, etc.). The more affluent people could afford small wooden tables having raised borders that were filled with sand (usually colored blue or green). A benefit of these counting boards on tables was that they could be moved without disturbing the calculation and the table could be carried and used indoors.
