Total exp:
6,355,741 exp
Sector games:
Easy: 13733
(Chances are he got 221 before med, hard mode, but Ross is going to calc it anyways.)
Med: 45
Hard: 72
Since med = 1.5x exp and easy = 1x exp;
45 med games x 1.5 = 67.5 easy games.
Since hard = 2x exp and easy = 1x exp;
72 hard games x 2 = 144 easy games.
Therefore total "easy games played" = 13733 easy games + 67.5 easy games + 144 easy games = 13,944.5 easy games (games "in" easy mode.)
6,355,741 exp / 13,944.5 games = 455.788 (sig) exp/game = 456 (calc) exp/game.