What the Numbers Say: A Field Guide to Mastering Our Numerical World

The bad news is that, in an age of science, complex financial planning, and competing deficit forecasts to support competing stimulus packages, the average citizen needs math more than ever. The good news, according to this delightful and eye-opening numeracy primer, is that it's all sixth-grade math. Niederman, a mathematics Ph.D, and author of The Inner Game of Investing, and Boyum, a public policy consultant, assert that quantitative competence is mostly a matter of simple habits of mind, including: trust numerical data over anecdotal observations, but always question what the data are really saying; think in terms of probabilities rather than certainties; and make rough-and-ready estimates so your calculations don't go off track. With such rules of thumb and a little arithmetic, the authors illuminate basic ideas about probability, statistics and measuring and comparing numbers. Their lucid, light-handed, equation-free style is based on a skeptical examination of the dogmas of our modern culture of quantity, in which they take a close look at such numerical sacred cows as the batting average, the body-mass index and the wind-chill factor; clarify the math behind public policy nostrums like Social Security privatization and the flat tax; and reveal what they see as the statistical distortions of The Bible Code and the reasons for taking Zagat scores with a few grains of salt. They conclude with some recommendations on instilling quantitative common sense in students (restricting calculators in the classroom is job one). This engaging book is a great challenge to fuzzy math of all stripes.