Includes bibliographical references and index.

Yogi Berra once went into a restaurant and ordered a pizza. When the cook behind the counter asked him if he wanted it cut into four or six pieces, he answered, "you better cut the pizza into four pieces because I'm not hungry enough to eat six." On a more serious note, in 1979, a student at Michigan State University disappeared; a potential suicide note was found in his room but his body was not. The student happened to be an avid Dungeons & Dragons player. Much media hype chalked his apparent suicide up to the role playing game and wondered if there could be a causal link: a string of other adolescent suicides and homicides occurred in the 1980s among D&D players. However, the rate of suicides among American teenagers at that time was about 28 per 1 million. The rate of the same among D&D players was just over 9 per 1 million. Ultimately, the number of suicides among D&D players was actually much lower than the national average, so the alarm about the dangers of D&D was unreasonable. In this book, James Zimring explores a specific kind of error in human thinking that we make when we're looking at, for example, risks and odds, probabilities, rates, percentages, and frequencies. These circumstances have one thing in common: they can all be represented as fractions. It is hard to navigate modern life without encountering and using these concepts. Exploring how fractions work and how we understand (and misunderstand) them can allow us to see why many of our deep seated intuitive thought processes, however they work neurologically, are susceptible to errors. It can also show us that what are errors in some settings can be great advantages in others. Overall, it can help us understand ourselves. As an aside, for anyone wondering: the MSU student described in the first paragraph called detectives about a month after his disappearance from the oil field where he was working in Louisiana and asked to be retrieved