LINQ aggregate functions on bytes, shorts, and unsigned values

How would you go about using LINQ aggregate functions (ex. Sum, Average) on collections of bytes, shorts, and unsigned values? Granted, I'm a new C# programmer, but I can't even figure out how to get something that compiles let alone has proper output.

Here's a trivial example of what I am trying to do:

short[] numbersArray = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
short sumArray = numbersArray.Sum();

or

List<short> numbersList = new List<short> { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
short sumList = numbersList.Sum();

I can't either of these samples to work. If I change the data type to int it works, but I can't get it to work for shorts, bytes, uints, etc.

What am I doing wrong?