# Blog 3: Book Review of “The Joy of x”, by Steven Strogatz

Steven Strogatz appeals to mathematicians of all competencies in The Joy of X. Using a personable charm and ingenuity Strogatz talks to readers of his book in such a way that anyone can grasp the mathematical properties he is explaining. Strogatz has the ability to take seemingly complex mathematical concepts and present reasons for such unfamiliar language then explains concepts that can help make understanding those complex problems easier.

Strogatz’s book is divided into thirty chapters, which are divided into six essential parts of any mathematical repertoire: Numbers, Relationships, Shapes, Change, Data, and Frontiers. He begins with intuitive explanations of basic concepts like place value, the four basic arithmetic operations, percentage increase and decrease, and solving equations, to higher levels of math, such as calculus, probability, statistics, group theory, and his thoughts on the nature of infinity. Each chapter is short, and could be read independently, yet the progression of topics is much akin to the progression of topics in traditional mathematics curriculum in school.

The discussion really does travel from the ground up, beginning with an illustration of a Sesame Street video, where Humphrey is serving a roomful of penguins, and relays their order to the kitchen as “Fish, fish, fish, fish, fish, fish,” which dovetails into a discussion on the number six. Humphrey understands that numbers make conversation more efficient, but at the price of using an abstract term to describe the penguins’ order (“six” is not nearly as implicit as “fish, fish, fish, fish, fish, fish”). The book goes on to explain the four basic mathematical operations, including an intuitive proof very similar to the one we used in class to demonstrate why a negative time a negative equals a positive. He furthers this explanation using the examples of how double-negatives relate to the firing of neurons (one nerve cell’s firing can be inhibited by a second nerve cells, but if that second nerve cell is inhibited by a third, the first can fire again – a chain of two negatives making a positive), and how multiplication with negatives can help analyze the shifting country-to-country alliances that lead up to World War One (if Country A is allied with Country B and Country C, it would be unbalanced for Country B and Country C to be enemies).

As you move through the rest of the book Strogatz offers brain teasers that keep the mind engaged (if an object is measured in yards, y, and you want to convert it to feet, f, what is the conversion equation? Not y=3f, as many would guess at first glance), and historical lessons that tell us why we do the math that we do today. Strogatz even provides insight into when is the ideal time in our dating lives to look for our soulmate.

I would definitely recommend this book to anyone, math nut or not, who would classify their self as a “student” of any sort. Strogatz’s ability to communicate mathematical concepts both easy and hard makes this book accessible for all. It was a very easy read, moved fairly quickly, and provided plenty of “aha!” moments that could give the reader pause for a moment as they think back on their own mathematical understanding, wondering why such concepts may have seemed so difficult, when Strogatz makes them seem so enjoyable.