Stone tablet shows Babylonians able to approximate √2 with 99.9999% accuracy
He explains the first row of symbols: 1, 24, 51, 10.  This represents 1 + 24/60 + 51/60^2 + 10/60^3 ~= 1.41421296, very close to sqrt(2) ~= 1.41421356.But what about the second row?The numbers on the second row are 42, 25, 35.  So I tried working out 42/60 + 25/60^2 + 35/60^3 and it works out to 0.70710648, which is very close to 1/sqrt(2) ~= 0.70710678.  So cool!