What the person above you is saying, I think, is to remember that computers usually work in base 2. This applies to IEEE floating points, where the mantissa is in base 2; when you represent fractions in base two, they're powers of two: 1/2 (.5), 1/4 (.25), 1/8 (.125), etc. What he's asserting, I think, is that any power-of-two fraction, or any combination of those (in binary), result in a number ending in 5 when represented in decimal. Anything else is going to be rounded to the nearest representable number (that ends in 5).

So, go might have that value in its source, but it's getting rounded to something that would, if represented in decimal, end in 5.