So if my students took a test and the best grade was an 83 out of 100, that student would not get an A, he would get a B on our scale (1o% for every grade starting at 100%, 90 A, 80 B, 70 C, 60 D, and 50 - F.) The United States scored a 63 out of 100. 100 being a perfect score on this scale.