A papyrus written around 1650 BC by a scribe named Ahmes, claiming he copied it from a source text dating two thousand years earlier. Along with the Moscow papyrus, it gives us the most information available on ancient Egyptian mathematics.

The papyrus measure 6 meters long and 1/3 meter wide, and contains 84 problems relating to unit division, geometric series, binary multiplication, and finding the area of a circle. This gives us a look into how the Egyptians determined their value for pi.

Here's how the problem goes. Take a circle, circumscribed inside a square. Divide the square into nine sections, as in a tic-tac-toe board. Obviously, the circle has an area of less than 9 units. However, it also obviously covers more than 5 units. Halving the corner units produces one half unit each, yielding approximately 7 units total. Taking 1.5 units as the radius of the circle, we find a value of pi of 3.1605.

More stuff about old math! Sanskrit and Mathematics