You just enter your grades exactly how they appear on your transcript. If you were mostly an A student it is a good thing for you actually, because the classes you would have gotten an A- in it will count as 4.0 instead of 3.7 (and A+ counts the same as A anyway). For grades of B and below you could get helped or hosed. Helped if it would have been a B- obviously, but hosed if it would have been a B+ under a different grading system. I had a couple more A-'s than B+'s in college so the +/- system actually lowered my GPA slightly, but only by like 0.02 or something.