Book excerpt: Regardless of whether they are housewives or auto mechanics, doctors or lawyers, or students or businessmen, The Smart Guide to Practical Math provides readers with responses to the questions they want answered about everyday math. From how many pounds of hamburger are required to make meatloaf to feed 12 people to how much to invest annually to be able to send a child to college, and whether it’s really a good idea to buy fuel additive for a car, this guide provides readers with practical mathematical formulas that can serve as templates for a number of real-life scenarios.