[Haskell-beginners] The numeric type stack

While haskell's type system is usually a delight to work with. However, every once and a while I need to do mixed mode programming in spite of Kernighan and Plauger's advice, and wind up cursing the numeric type stack. I was wondering it there was a writeup on it somewhere? Preferably one aimed at practical programming. A chapter in Real World Haskell would have been ideal, but it doesn't seem to exist. Thanks,