See here :
16 answers chosen as best : 20 (points from best answers) * 16 = 320 points
Received 33 up votes : 33 * 10 (points) = 330 points
330+320=650 points
Received 9 down votes : 9 * 2 points (you said that 1 down vote = 2) = 18 points
Right now i have 484 points
650-18= 632 points , 632-484=148 points are mising ,where are they ?