Cover: Practical Algebra by Steve Slavin, Bobson Wong, Larisa Bukalov

Wiley Self-Teaching Guides teach practical skills from accounting to astronomy, management to mathematics. Look for them at your local bookstore.

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All the Math You'll Ever Need: A Self-Teaching Guide, by Steve Slavin

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Practical Algebra: A Self-Teaching Guide, Second Edition, by Peter H. Selby and Steve Slavin

Quick Algebra Review: A Self-Teaching Guide, by Peter H. Selby and Steve Slavin

Quick Arithmetic: A Self-Teaching Guide, by Robert A. Carman and Marilyn J. Carman

Quick Business Math: A Self-Teaching Guide, by Steve Slavin

Quick Calculus: A Self-Teaching Guide, Second Edition, by Daniel Kleppner and Norman Ramsey

Statistics: A Self-Teaching Guide, by Donald Koosis

Practical Algebra

A Self-Teaching Guide

Third Edition

 

Bobson Wong

Larisa Bukalov

Steve Slavin

 

 

 

 

 

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ACKNOWLEDGMENTS

Writing a book is hard. Writing a book while teaching full-time during a pandemic is even harder. Fortunately, many people helped make this edition of Practical Algebra a reality. Our students' mathematical struggles and joys over the years inspired us to write this book. Conversations with our colleagues at Bayside High School and Math for America helped us develop many of the ideas and techniques we describe. Bayside students Juliana Campopiano and Queena Yue helped us proofread the text. The team at Desmos designed a powerful online graphing tool that we used to create the graphs in this book. The staff at John Wiley & Sons (especially Pete Gaughan, Christine O'Connor, Riley Harding, Julie Kerr, and Mackenzie Thompson) have been especially patient and supportive. Larry Ferlazzo introduced us to publishing math books, opening up countless opportunities. Finally, our spouses and children deserve special mention for tolerating our conversations about this book, peppering us with mathematical questions over the years, and helping to keep our work in perspective.

INTRODUCTION

What is algebra? You may associate it with solving equations such as 2x + 7 = 19. However, both the history of algebra and the way that it's taught today show that algebra is much more. For thousands of years, people solved algebraic problems without symbols such as x and +. By the 9th century, people including the Persian mathematician Muḥammad ibn Mūsā al-Khwārizmī had popularized the idea of using an algorithm (a set of well-defined instructions) to determine unknown quantities. In fact, the word algebra comes from the Arab word al-jabr, meaning “the reduction,” from the title of al-Khwārizmī's most famous mathematical text, Kitāb al-jabr wa al-muqābalah. Symbolic notation didn't become widespread until European mathematicians such as François Viète and René Descartes developed them in the 16th and 17th centuries. Nowadays, algebra courses include not just equations but also functions (the special rules that define mathematical relationships) and real-world modeling with statistics. In short, today's algebra students must know how to understand word problems, make and interpret graphs, create and solve equations, and draw appropriate conclusions from data.

Not surprisingly, algebra makes many people nervous. Maybe you recall endless drills and elaborate procedures from years ago. Perhaps you're a middle school or high school student who's intimidated by the high level of abstract reasoning that's required. If so, you're not alone. We understand how you feel! For many years, we've taught all levels of high school math, so we have a lot of experience working with diverse learners. This book contains concrete strategies that help our students succeed. We strongly believe that people can get better at math if they have access to the right tools.

We wrote this book as a general introduction to algebra. We assume that you're familiar with basic arithmetic (adding, subtracting, multiplying, and dividing numbers) and fractions. If you're not comfortable with these topics, don't worry—we briefly review them in Chapters 1 and 2. Even if you are comfortable with them, we suggest that you look through these chapters anyway. We explain why these ideas work and how they're related to the algebraic ideas we discuss later on.

Each chapter in this book is divided into sections, with model examples and tips. At the end of each section, you'll find several exercises to help you practice and apply your skills. These exercises include what we call Questions to Think About (open-ended questions designed to help you think about important concepts) as well as dozens of word problems. Each chapter has a test with multiple-choice and open-ended questions. The solutions to all exercises and chapter tests are located at the end of each chapter.

As you work through this book, you'll see some important ideas about algebra that we emphasize:

  • Algebra is a language. We believe that many people find algebra intimidating because the words and symbols we use, such as polynomial, an, and f(x), literally look like a different language. In addition, we don't just write math, we also read and speak it. In the Reading and Writing Tips, we discuss how to write and pronounce mathematical symbols as well as how to use them in context. We also include a glossary of mathematical terms and symbols in the back of the book.
  • Algebra should make sense. We believe that algebra should be taught in a way that makes sense. In our experience, part of the reason why so many people suffer from math anxiety is that they see it as a collection of disjointed and confusing tricks. Throughout this book, we use techniques (such as the area model for multiplication) that relate to other mathematical topics, such as geometry and statistics. By making these connections, you can extend what you learned in one situation to another context, which will strengthen your mathematical skills and boost your confidence!
  • Algebra requires pictures. As we taught during the pandemic, we had to adjust our instruction. We couldn't be with our students in person, so they often had to teach themselves more independently. Incorporating graphs, tables, diagrams, and other images into our teaching helped our students make sense of math. Since this book is a self-teaching guide, we've included many visual strategies throughout this book.
  • Algebra requires technology. Calculators, computers, and other technology aren't just shortcuts for menial computations. They are now required for today's complex modeling tasks. Using technology helps us to see patterns more efficiently. Since each of these tools has vastly different user instructions, we don't include specific instructions for each device. Instead, we include Technology Tips that apply no matter what device you're using.
  • Algebra is a human endeavor. We believe that algebra should not be perceived as a set of rigid rules developed by a select group of people. In fact, as we note throughout this book, many mathematical concepts were developed in different cultures around the world over thousands of years. (We mention some of the more interesting stories in the Did You Know? callouts.) In addition, we recognize that making mistakes is a natural part of doing math. In the Watch Out! callouts, we point out many of the common errors that we've seen students make over the years so that you can avoid them!

We hope that as you work through this book, you'll find that algebra can be less intimidating and more meaningful than you originally thought.

Bobson Wong and Larisa Bukalov