The mysterious art of addition

Today John came up to me and showed me some pretty strange stuff.

He added some double values, ending up adding 88.9 and 11.2, with an effective value of 100.1000….009.

This seemed a little bit odd, but maybe I just suck at math, after some studies using the calculator we figured out, that .Net has some problems adding these values, more research revealed that this has to do with floatingpoint operations and rounding problems, which every programming language has to face.

Here you find some pretty good articles on this topic:

http://www.developerfusion.com/article/4691/floatingpoint-in-net-part-i-concepts-and-format/

http://www.lahey.com/float.htm