Also known as Pythagoras’ constant, the square root of 2 is a positive real number that, when multiplied by itself, results in the number 2. Though perhaps less well known than pi, the square root of 2 was probably the first known irrational number—a real number that cannot be expressed as a ratio of two integers—and approximations of it have been found on an ancient Babylonian tablet and in ancient Indian texts. To how many decimal places has the value of the square root of 2 been calculated? Discuss
Source: The Free Dictionary