I'm bad at math so I don't really know how to calculate the winnings(or losing) at the end of the match. Somebody tell me how that works?

There's no real math involved.
It's just like this:

Favored gets less rating, and loses more rating.
Even gets a balanced amount of rating. Loses a balanced amount of rating.
Not favored gets more rating. Loses less rating.

If you really want to know the exact details of how it works, look here:
http://en.wikipedia.org/wiki/Elo_rating_system

with equal rating one winning would get about 16.
I find that The amount you get when you win vs the amount you lose when you lose tend to add up to around 32, but this isnt always the case.

It's based on probability of a win. If a 1200 beats a 2k, they'll get a ton of rating (caps around 32 I think) and the 2k will likely get 0-1 rating.