The world of floating points

From time to time in a word of computer scientist a question is raised, that for the first look is hard to figure. I remember few years ago there was a big deal about incorrect answer to a really simple algebra problem in MS Excell. Usually this class of problems deals with some math basics, that every computer scientist knows (at least I hope for that), but the knowledge is really rusty - not often used, so the answer doesn't come to a mind. A day ago a great question was raised dealing with a floating point arithmetic, for the first look at the question I wouldn't even guest that it is because we might deal with floating points. But ofcourse the answer is correct, and what's more it leads to a great article, a good read.