The Mathematics of Everyday Life

Explore the marvel Albert Einstein called “the eighth wonder of the world”—compound interest, which is the strategy of reinvesting interest rather than paying it out. Simple calculations show that a retirement nest egg of $1 million or more is within reach for those who start investing early. Learn why the average rate of return can be misleading. Also get tips for building a college fund.

The miracle of compound interest that enriches savers can make paupers of those with credit card debt. Learn why this form of borrowing is so risky and potentially ruinous. Explore strategies for paying off credit card debt and consider whether it makes sense to keep credit cards for perks. Then look into college loans, weighing costs versus benefits, and also examining alternatives to loans.

Over our working lives, many of us spend a total of a year or more driving to and from the office. Is it worth it? Professor Omar uses simple calculations to assess the true costs of commuting, taking into consideration the relative price of real estate in the city and suburbs, the expense of cars and upkeep, and not least the psychological toll of sitting in a traffic jam day after day.

Investigate numbers you are likely to encounter in the doctor’s office. What do body mass index (BMI) and blood pressure signify? Both correlate measured values with possible health issues. But as you learn, correlation does not imply causation. Also consider questions to ask when faced with statistics for different medical treatments, bearing in mind a phenomenon called Simpson’s paradox.