Or think about it like this -
Take how many inches you need to come up, and divide by the # of hundreds of yards. Remember though that MOA is not exactly 1" at 100yds, actually 1.047" if I remember right this early. So not a big deal 'til you start getting out there a bit.
Examples - need to come up 6" at 300yds, 6/3 = 2MOA up; 18" at 400yds, 18/4 = 4.5MOA up.
Make sense?
