I am not going to work through your proggie (I'm lazy)
Insert intermediate result prints after each calc step and step through the routine and watch what happens to your numbers.
jasimp commented: You have to stop knowing something about everything ;) +9
Ancient Dragon commented: Good one :) +36
nav33n commented: :D You scared him away. I don't think he will ever return! +10
Ezzaral commented: Everyone should have at least two of those! +18
Gerryx1 commented: Well thought out shows good reasoningd lod +3