# The Handy Math Answer Book

##### Introduction

We’ve all seen it. We’ve all experienced it, many times without knowing it. It’s in the design of a beautiful stained-glass window in the middle of an Austrian cathedral. It’s in the large and small workings of a car, computer, or space shuttle. It’s in the innocent statement of a child asking, “How old are you?” By now you’ve probably guessed what “it” is: mathematics.

Mathematics is everywhere. Sometimes it’s as subtle as the symmetry of a butterfly’s wings. Sometimes it’s as blatant as the U.S. debt figures displayed on a sign outside the Internal Revenue Service building in New York City. Numbers sneak into our lives. They are used to determine a prescription for eyeglasses; they reveal blood pressure, heart rate, and cholesterol levels, too.

Numbers are used so you can follow a bus, train, or plane schedule; or they can help you figure out when your favorite store, restaurant, or library is open. In the home, numbers are used for recipes, figuring out the voltage on a circuit in an electric switchbox, and measuring a room for a carpet. Probably the most familiar connection we have to numbers is in our daily use of money. Numbers, for instance, let you know whether you’re getting a fair deal on that morning cup of cappuccino.

The Handy Math Answer Book is your introduction to the world of numbers, from their long history (and hints of the future) to how we use math in our everyday lives. With more than 1,000 questions and answers in The Handy Math Answer Book (1,002, to be mathematically precise) and over 100 photographs, 70 illustrations, and dozens of equations to help explain or provide examples of fundamental mathematical principles, you’ll cover a lot of ground in just one book!

Handy Math is split into four sections: “The History” includes famous (and sometimes infamous) people, places, and objects of mathematical importance; “The Basics” explains the various branches of mathematics, from fundamental arithmetic to complex calculus; “Math in Science and Engineering” describes how relevant math is to such fields as architecture, the natural sciences, and even art; and “Math All Around Us” shows how much math is part of our daily lives, including everything from balancing a checkbook to playing the slots in Las Vegas. The subject of math and its many connections is immense.

After all, over two thousand years ago the Greek mathematician Euclid wrote thirteen books about geometry and other fields of mathematics (the famous Elements). It took him six of those volumes just to describe elementary plane geometry.

Today, even more is known about mathematics, as you’ll see in the list of resources described in the last chapter of this book.

Here we’ve provided you with everything from recommended print sources to some of our favorite Web sites, such as “Dr. Math” and “SOS Math.” In this way, Handy Math not only introduces you to the basics of math, but it also gives you the resources to continue on your own mathematical journey. Be warned: This journey is an extensive one. But you’ll soon learn that it’s satisfying and rewarding in every way. Not only will you understand what math all is about, but you’ll appreciate the mathematical beauty that surrounds you every day. Just as it has astounded us, we’re sure you’ll be amazed by how numbers, equations, and sundry other mathematical constructions continue to not only define, but also influence, the world around us.