On Thu, 29 Oct 2009, Aldric Giacomoni wrote: > Matthew K. Williams wrote: >>> irb(main):016:0> 123.6 - 123.0 >>> => 0.599999999999994 >>> >>> That's a little strange.. Isn't it? >> >> No, it's not. Welcome to the wonderfully confusing world of floating >> point math... > > Oh, thanks. Can I have some pop-corn and an introductory pamphlet before > I bash my head against the wall? :) Pamphlet -> http://en.wikipedia.org/wiki/IEEE_754-2008 Popcorn, well, it's kinda hard to transmit over the wire. ;-) As a rule of thumb, if you really care about the decimals, either use BigDecimal or integers (and keep track of where the decimal should be -- this is common for $$$$). Unfortunately, this is not limited to ruby, either -- C, Java, and a host of other languages all are subject. Matt