After growing woefully bad at mental arithmetic, I purchased this book in preparation for an MBA program this fall. It is amazing how much "Mental Math" has helped me regain my confidence and improve my math skills. You should note, however, that this book doesn't offer any magic secrets. The book offers systematic approaches toward mental math, but it takes practice and effort to master these basics. I tend to practice by pulling numbers off of license plates while I'm on the road and performing different arithmetic operations on them in my head. To practice with more "real world" examples, I take numbers from business magazines and made appropriate calculations (percentage increase/ decrease in profits, etc). I hope you get as much from the book as I have!