You must cross the Pit of Doom by swinging over it with the Rope of Justice, then brave the Alligators of Incontenence and Ladders of Easily Breakable Wood. If you manage to fight yourself past the Cave Monsters of Horizontal Traveling you may find yourself in the presence of the Great Lemon. He shall ask you one riddle and if you answer this riddle correctly ("how many fingers am I holding up?") you shall be granted the great and amazingly-useful Math Ear.

But yeah. The hardest parts of calculus is the algebra required to tackle some of the problems. Know the formulae and how to write the answers (thank you very MUCH, Mrs. Thomas) and you'll fine.