Most machines in the game have multiple lines, which are patterns the symbols need to line up in to qualify as a win.
The bet you place while spinning is divided up among each of these lines. If you get wins on multiple lines, most machines will cycle through them until the next time the spin button is pressed. For every line that is a winner, the portion of the bet that was divided onto that line is increased by the multiplier.
You can find out how many lines each machine has by checking the paytable in the lower left hand corner. With that information, you can calculate the total wins like so:
(bet)/(lines)*(multiplier for winning line 1) +
(bet)/(lines)*(multiplier for winning line 2) +
(repeat for any more winning lines)
= total win
For 144 or 243 line machines you'll need to use a different number that varies depending on the machine, let us know if you want more info.
If you have any questions, please let us know using the "Contact Us" feature.