Hmm... well, clearly I don't deserve an A, since I failed to do execute elementary arithmetic algorithms correctly!
Sorry about that!
The way the Moodle gradebook is currently handling it is that every category gets weighted slightly less.
For instance, the Final Exam is being valued at 20/110 = 18%, and the pop quizzes are valued at 6/110 = 5.45%, etc. This seems like it's probably the most reasonable approach to me...