In Reply to: Wanting to do cheat sheets for 2 posted by lovesamsbar on Monday, 20. September 2010 at 10:15 Bali Time:
I tend to work it out off a round number - Rp8000 on this last trip, even though the rate varied by a few hundred rupiah during our stay.
The difference really adds up to not much at all. As an example, Rp100K using 8000 as the rate is $12.50 and using 8400 it's $11.90, so you're really only talking about 60c difference for every Rp100K in price.
Print one off at 8400 if it's easier. The price will be within a dollar of what the cheat sheet says, and the rates change from day to day. If you worry about being too perfect, it'll only be wrong within a day or two anyway.