You SHOULD know what you are asking, because if YOU don't know what you're asking, then how can anyone else? But I'll do my best...
The most you should need to know is conversions. There aren't really any formulas like in Solar System or some of those other events. For example, know how to convert Fahrenheit to Celsius to Kalvin and back, how to convert Millibars to Inches in Mercury, how to change Miles per Hour into Knots, and maybe just to be on the safe side know some measurement conversions, like feet to yards, etc.
"Let's put all our differences behind us, for science. You monster."
Ubuntu is awesome.