How to perform arthematic operations on two numbers

Hey RYAN Your tutorials are gr8. Still had’nt completed them though…
I was wondering is there any way to perform arithmetic operations on two numbers?? Think of a kind of calculator. Actually i m trying to build a site where employees submit their articles and their amount just add’s up (after multiplying it with the number of words )and it also keeps their record of number of articles. Actually im stuck in the arithematic part.. is it possible to perform operations on two numbers in seperate text area in expression engine. And can u share us some syntax for it.