Hey Windell I was wondering how to do hexadecimal calculations in the Arduino IDE (if it's even possible).
Thanks.

Yes, you can use hexadecimal representations of any number in C. See, for example: http://arduino.cc/en/Reference/IntegerConstants

Thanks.

So can I just add, multiply, divide, and subtract the numbers the numbers on their own? Like 0x3B / 0xF

There's no difference to the compiler whether you speak decimal or hexadecimal-- both are foreign languages. It speaks binary.

Okay, now would I be correct in saying that you can only store hexadecimal in a byte variable?

Also I tried to divide a byte variable by a byte variable and it said something along the lines of error using type byte[1] [1] and byte[1] [1] with operator /.

Hexadecimal is like decimal, it's just a different representation of numbers... It just happens to "fit" with binary better, as 16 is a power of 2 (which also makes it easier to visualize the individual bits, once you're familiar with it). There's no "size limit" to hexadecimal, any more than there is a limit to decimal.

A byte (8 bits) could be shown as 255 in decimal, or FF in hexadecimal (or 11111111 in binary). If you have a bigger number, it takes more digits, just like you'd expect. 16 bits would use four hexadecimal digits instead of two.