Actually, it wasn't me saying that VS2005 didn't have it. I know that 2005 is an IDE. Which is why my question was, if he's using C# doesn't he have System.Math? But, I guess looking at it, System.Math doesn't have an average function (also generally known as mean and what Linq uses). Really, though, you don't need to have a mean function to calculate the mean, it's about as basic a function as you can write. I just wanted to make sure I wasn't crazy thinking that any version of C# had a System.Math library.