From "A History of Pi" by Petr Beckmann, a mathematician from Czechoslovakia.

"In 1936, a tablet was excavated some 200 miles from Babylon. Here one

should make the interjection that the Sumerians were first to make one of

man's greatest inventions, namely, writing; through written communication,

knowledge could be passed from one person to others, and from one

generation to the next and future ones. They impressed their cuneiform

(wedge-shaped) script on soft clay tablets with a stylus, and the tablets

were then hardened in the sun. The mentioned tablet, whose translation

was partially published only in 1950, is devoted to various geometrical

figures, and states that the ratio of the perimeter of a regular hexagon

to the circumference of the circumscribed circle equals a number which in

modern notation is given by 57/60 + 36/(60^2) (the Babylonians used the

sexagesimal system, i.e., their base was 60 rather than 10).

The Babylonians knew, of course, that the perimeter of a hexagon is

exactly equal to six times the radius of the circumscribed circle, in fact

that was evidently the reason why they chose to divide the circle into 360

degrees (and we are still burdened with that figure to this day). The

tablet, therefore, gives ... Pi = 25/8 = 3.125."