Practical exercises and information that you can put to immediate use. Find out interesting things about how calculators work, and how best to get a handle on your income and expenses. Learn to check your paystub, invoices and bank statements for errors and overcharges, and become more skilled at handling money and comparing investment opportunities. Learn how to calculate percentages, including the proper amount to pay in tips, commissions, taxes and discounts. Find out how to calculate interest rates and develop a better understanding of mortgages, credit cards and other types of loans. Discover a handy method for converting one type of measurement to another, and learn to calculate areas correctly so you don't overspend on your next home improvement project. Learn to interpret graphs, calculate the probability that something will (or won't) happen, and understand the statistics embedded in test results, polls and news stories.