This book is designed for you. Its main purpose is to get together in one place a wide variety of useful and interesting information involving calculators, the world around you, and mathematics. It's designed to be a working tool that, when used with your calculator, becomes a system for problem solving as well as a key to discovery. We hope you'll have fun reading and exploring with it.
The Story of Mathematics
It is said that mathematics began long ago in Early Egypt. The Nile River would flood on occasion and wash away all landmarks and monuments. People needed a way to know where their land was after these floods, so methods of earth measurement (later to be called Geometry) were invented. The Greeks, always thinking, picked up those techniques, developed them further, and added new ideas such as Algebra and Trigonometry. Math was off and running. It was used in oceanic exploration. It was interesting. It was fun. Mathematics was used to help learn about the ways in which the world worked, what it looked like, and how much things cost. Calculus, statistics, and income taxes were invented.
The Story of Calculators
As mathematics began to grow, people started to notice that there were some parts of it that were not nearly as much fun as others. Downright tedious, in fact. Getting answers not only involved looking carefully at nature and people and analyzing them (fun part), but also often involved adding, subtracting, multiplying and dividing very cumbersome numbers (not so much fun part). People began looking for tools to help them handle the arithmetic part of mathematics more easily.
First, stones were used for counting things and keeping track. Then these were placed on a lined table or strung on a frame to form the abacus (a device still widely used in many parts of the world.) Calculating tools then evolved — somewhat slowly—and a series of mechanical devices developed starting in the 1600's with ideas from men such as John Napier. The first real calculating machine was invented by a Frenchman named Blaise Pascal — for handling monetary transactions. It was a complex entanglement of gears, wheels and windows. Next came even more complex whirling and whizzing mechanical units, with buttons, wheels and hand cranks. Bigger machines using relays and punched cards came about as electricity was applied to mathematics in helping take the 1890 U.S. Census.
Computers were born and began to grow. Sliderules (easy to use and much more accessible than computers) were invented to help take some of the tedium out of long calculations.
Math on Keys
Then, a few years ago, people working in electronics began making some breakthroughs that resulted in the inexpensive, accurate and reliable hand held calculator. "Math on Keys" became available to everyone. Now, throughout the world, people are finding these little devices to be powerful allies as they handle numbers and math in their everyday five's.
Math is all around us and is part of many daily activities. Your calculator allows you to handle many of these problems quickly and accurately—without having to hassle with lengthy,
tedious computations. This book has been designed to show you how. What we've tried to do is put together an accessible and compact package of the principles you need to take your problems and easily work them with keyboard solutions. This book was designed to work together with your calculator — to open up all its secrets and let you have more complete access to its power. Use them together! Both of them have been designed for you.
Experiment! Find how many heartbeats in a lifetime. How many Saturday nights are there until you're 85? What's the best buy? What's your correct change?
The first step is to really get acquainted with your calculator— to put it through its paces and see all aspects of how it operates. Chapter I of this book is a quick "tour" of the features and keys on your calculator; along with a brief look at why each key or feature is there, as well as how each can be useful. This "tour" is important — it will familiarize you with the full scope and power of your machine. The subsequent chapters are packed with approaches to common mathematical problems in a variety of fields and the details you'll need in putting together quick, accurate solutions on your calculator. Along the way you'll find some bits of history or challenging ideas that may take you beyond a specific problem into further explorations with numbers.
Remember, too, that although your calculator is packed with the latest in state of the art solid state technology, it needs love and respect, as well as occasional use as a toy. Don't be afraid to play with it — it's rugged and durable enough to be used anywhere. You may find yourself exploring patterns and relationships which can lead you to a whole new appreciation of the beautiful side of numbers and mathematics.