Now this is a rough question to answer as each casino has their own method. You usually find #'s on the machine glass. They use a label maker tape. It is necessary to have them in plain view so as not to confuse the drop teams and audit people!

I used to put them on the reel glass (one side for machine# and the other for Bank/stand #. When I moved a machine the stand/bank # would change, but NEVER the machine # unless I had changed the program (required change of number!!!!). The stand/Bank # is also used by surveillance to identify where something is happening!

Alot of N Nevada use the following or similar. Usually a stand # will have an alpha character in it.

1000-2000 range= 5 cent
3000-4000 range = Q
5000 Range - Dollar etc.
I used 9000 for multi denom.

A key is the color of the candle. red=Nickle, yellow-Q, blue=Dollar. Try to find some semblance of the numbers on the front of the machine (could even be on the slot stand but not usually) and the range of numbers matching a vertain color candle.