## INTRODUCTION |

It never occurred to us that mathematics would change so much in just over a half decade. We found that mathematical research continually metamorphoses not only scientifically, but socially, economically, and even emotionally. Such changes have become a necessity in our globally challenged and connected world. Just to write this book for you, many people along the way had to know about mathematics—to code a program to write, edit, and space our words for—and even mathematical codes so we can type “mathematics” without misspelling it!

And of course, mathematics doesn’t end with computers; math and numbers surround us everywhere. It’s found in the vegetarian recipe book you just bought (for example, you have to understand volume measurements) and on your containers of medications (how many and how much per day). Math allows you to get change back from that espresso you bought at the local café (and how much to tip the barista), and is even necessary when you drive (not exceeding the speed limit is all about knowing numbers).

On a larger scale, mathematics and numbers are part of our economy (think banking, what we buy, and how banks figure out credit card balances); it’s part of our political system (voting and polling use statistics, and even our government has to use math to balance the nation’s “checkbook”); and it’s even part of our health system (almost everyone knows about blood pressure, glucose, and cholesterol numbers—not to mention how to figure out health insurance coverage). Mathematics and numbers followed us to the Moon and back, helped ancient and modern civilizations build monuments and cathedrals, and were even used to build the bridge you cross every day on your way to work.

As with the first edition, this newly revised *The Handy Math Answer Book* answers over 1,000 questions about the who, what, where, how, and why of mathematics. It delves into the long history of mathematics—how using numbers began to our modern use of numbers—to the branches of mathematics, from algebra and geometry to statistics and calculus. The book covers history, including people, places, and objects that are important to the overall view of mathematics; the basics, including the various main branches of mathematics; math in the sciences, including engineering, natural sciences, and computers; and math all around us, explaining ways mathematics is used in our everyday lives, from balancing a checkbook and determining our mortgage to playing the gaming tables at a casino.

This book is only the tip of the mathematical iceberg; there is a great deal more to learn below the surface when it comes to math. Thus, we also offer an up-to-date listing of resources—from websites to visit to books and magazines that will help you continue your mathematical journey.

Be aware, too, that the journey is not only amazing, but fascinating and captivating. And, as one of Patricia’s math professors used to jokingly profess, “Math is radical!” or the more subtle, “Calculus has its limits.” After you read this book, you’ll understand why.