Do you wake up in cold sweat thinking about how to calculate the slope of a parabola? Does the feeling of not knowing what derivatives really are strike fear in your heart? In that case you may have to work out the problems beyond the scope of those covered within the pages in this book. Luckily if you are just curious about calculus and feel like nobody has really explained it to you then you might as well give this book a try. Not only is the book short, and quite possibly instructive but it features a picture of a studied dog that has nothing to do with mathematics. You should also note that despite the laws of economics you can read the entire book free of charge and nothing bad will happen (those who complain about opportunity cost will be be sent a bill at a later time).