MD, it is indeed the case that hansda has no idea what he's talking about. There is no such mathematical entity as .000...1. I would simply ask hansda to name the index at which the '1' appears. To elaborate on this point: The decimal notation .abcdef... means by definition the sum of the infinite series a/10 + b/100 + c/1000 + ... In other words given a positive integer position n, we know what digit a_n is in decimal position n. A number in decimal notation is really a function whose domain is the natural numbers 1, 2, 3, ... and whose range is the set of decimal digits zero through nine. The problem with the .000...1 idea is that you can't tell me which index position the '1' is in. This notation is simply not defined. It's meaningless.