how do you multiply ohms by Milliamps and come out with an answer that makes sense? Isn't that kind of like comparing apples to oranges or combining a tractor with a reading lamp?
It only seems like you're multiplying unlike terms because in electronics we use a convienent shorthand to simplify our calculations.
Amps (or more properly, Amperes), is the number of Coulombs of charge passing through a given point in one second, or Coulombs / second (C/s)
Voltage can be defined as the amount of potential work in Joules per Coulomb of charge, or J/C. (This is an oversimplification but it will do for now.)
Multiplying Amps by Volts gives (J*C)/(C*s) which simplifies to J/s or Joules per second. (The Coulombs cancel out)
Now Joules can also be defined as Newton-Meters of work but in electronics we generally prefer the definition Watt-seconds, or (W*s). Substituting this for Joules gives (W*s)/s (The seconds cancel out) leaving W or Watts!
So Watts = Volts times Amps and all units are correct.
As for Ohms, see if this helps: http://en.wikipedia.org/wiki/Ohm
Personally, I'd hate to be forced to do all my calculations in kilogram-meters squared per seconds squared (kg*m2
But maybe that's just me.