Barry Cipra 
Misteaks. . . and how to find them before the teacher does. . . [PDF ebook] 
A Calculus Supplement, 3rd Edition

An unusual supplement to every calculus textbook, Misteaks and How to Find Them before the Teacher Does is popular with students and teachers alike. Teachers love the way it encourages students to truly think about mathematics rather than simply plugging numbers into equations to crank out answers, and students love the author»s straightforward, tongue-in-cheek style. The title of this light-hearted and amusing book might well have been ‘Going Gray in Elementary Calculus and How to Avoid it.’ Changing the metaphor, Barry has hit the nail on the finger in hundreds of fine examples. —Philip J. Davis, coauthor of The Mathematical Experience. ‘How I wish that something like this had been available when I was a student!’ —Ralph P. Boas, former editor of The American Mathematical Monthly. Bonus: Solution to Le Witt Puzzle