How did the Babylonians know √2 up to six digits?
The greatest known computational accuracy in the ancient world
This clay tablet from 1800-1600 BC shows that ancient Babylonians were able to approximate the square root of two with 99.9999% precision.
How did they do it?
Deciphering the tablet
First, let’s decipher the tablet itself. It is called YBC 7289 (short for the 7289th item in the Yale Babylonian Collection), and it depicts a square, its diagonal, and numbers written around them. Here is a stylized version from the book Episodes from the Early History of Mathematics by Aaboe Asger.