Page "Abacus" Paragraph 9

A tablet found on the Greek island Salamis in 1846 AD dates back to 300 BC, making it the oldest counting board discovered so far.

It is a slab of white marble long, wide, and thick, on which are 5 groups of markings.

In the center of the tablet is a set of 5 parallel lines equally divided by a vertical line, capped with a semicircle at the intersection of the bottom-most horizontal line and the single vertical line.

Below these lines is a wide space with a horizontal crack dividing it.

Below this crack is another group of eleven parallel lines, again divided into two sections by a line perpendicular to them, but with the semicircle at the top of the intersection ; the third, sixth and ninth of these lines are marked with a cross where they intersect with the vertical line.