“Can you solve a tricky applied mathematics problem in just three seconds? Why is it important to make sure you have units and dimensions right? How can you estimate unknown quantities to a decent approximation? How do you construct simple, yet visually striking, proofs? How do you go from a simple approximation to a better one? Can you solve a very, very difficult problem by solving a simple version of it first, and then applying this solution to the harder problem?

Do you like math but tired of going over complicated proofs and learning specialized techniques that are only useful in a very narrow area of mathematical problems? Would you rather read a mathematics textbook that gives you a powerful toolbox of neat tips and tricks to handle diverse problems in many different areas? That allows you to find good approximate answers to questions that are very difficult to solve exactly? Then this textbook is for you.”