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CCBC Math 081 Textbook 3rd Edition
Chapter Sections Page
Chapter 1 Integers
1.1 Introduction to Integers 1.2 Absolute Value 1.3 Addition of Integers 1.4 Subtraction of Integers Mid-Chapter 1 Review 1.5 Multiplication and Division of Integers 1.6 Exponents and Roots 1.7 Order of Operations Chapter 1 Summary Chapter 1 Review
1 11 17 23 41 43 52 61 68 70
Chapter 2 Applications of Integers
2.1 Translation of Words into Expressions 2.2 Geometry Mid-Chapter 2 Review 2.3 Statistics: Mean, Median, and Mode 2.4 Bar Graphs, Line Graphs, and Tables 2.5 Applications Chapter 2 Summary Chapter 2 Review
72 81 100 102 109 121 129 131
Chapter 3 Fractions
3.1 Introduction to Fractions 3.2 Multiplication of Fractions and of Mixed Numbers 3.3 Division of Fractions and of Mixed Numbers Mid-Chapter 3 review 3.4 Addition of Fractions and of Mixed Numbers 3.5 Subtraction of Fractions and of Mixed Numbers 3.6 Order of Operations 3.7 U.S. Measurement Conversions 3.8 Application Problems Chapter 3 Summary Chapter 3 Review
137 160 177 186 188 211 229 235 244 257 260
Chapter 4 Decimals
4.1 Introduction to Decimals 4.2 Converting Between Decimals and Fractions 4.3 Addition and Subtraction of Decimals Mid-Chapter 4 Review 4.4 Multiplication and Division of Decimals 4.5 Metric Measurement 4.6 Applications Chapter 4 Summary Chapter 4 Review
263 276 283 296 298 314 322 336 338
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Chapter 5 Algebra
5.1 Introduction to Algebra 5.2 Algebraic Properties 5.3 Distributive Property Mid-Chapter 5 Review 5.4 Solving Equations Using the Addition Property of Equality 5.5 Solving Equations Using the Multiplication Property of Equality 5.6 Solving Equations Using the Addition and Multiplication Properties of
Equality 5.7 Translating English Sentences into Mathematical Equations and Solving Chapter 5 Summary Chapter 5 Review
344 357 380 386 387 396 403 413 420 422
Chapter 6 Ratios, Rates, and Proportions
6.1 Ratios 6.2 Rates 6.3 Unit Rates Mid-Chapter 6 Review 6.4 Proportions 6.5 Applications Chapter 6 Summary Chapter 6 Review
425 431 435 442 443 450 459 460
Chapter 7 Percents and Applications
7.1 Introduction to Percents and Conversions Among Fractions, Decimals, and Percents
7.2 Translating and Solving Percent Problems Mid-Chapter 7 Review 7.3 Circle Graphs 7.4 Financial Applications of Percents 7.5 Application Problems Chapter 7 Summary Chapter 7 Review
467 478 488 490 502 516 526 528
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Dedication
This book is dedicated to all of the hard working CCBC Students taking Math 081. We hope that you will
be very successful in your mathematical journey, having had a solid foundation after completing this
course.
Nearly all Community College of Baltimore County Mathematics Department faculty members
contributed in some way to the production of the textbook.
Thank you to the following CCBC faculty members who edited portions of the Math 081 textbook for the
3rd edition:
Kathy Baranoski
Tim Howell
Lisa Sallee
Molly Stube
Tejan Tingling
Cathy Permut
A special thank you to the following CCBC faculty members for leading in the editing and rewriting of the
Math 081 textbook for the 3rdedition:
Jean Ashby
Lisa Brown
Alberta Latorre
Thank you to the following CCBC faculty members who produced the videos for the 3rd edition of the
Math 081 textbook:
Chapter 1 – Lisa Brown
Chapter 2 – Sarah Miller
Chapter 3 – Lisa Brown
Chapter 4 – Sarah Miller
Chapter 5 – Bob Brown
Chapter 6 – Sarah Miller
Chapter 7 – Lisa Brown and Greg Stiffler
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This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License.
To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/.
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To the student,
For each written example in this textbook, you will find a similar practice problem with a video link to a
YouTube video. You can access an online version of the textbook at:
http://www.ccbcmd.edu/math_science/math/math081text.html
You can watch each problem individually by clicking on the online version’s link, or you can type in the
printed link into any browser. At the end of each section you also have the option to watch all of the
problems in that section in one video by clicking on the link or entering in the printed link that follows
“Watch All:”.
At the end of each section, you will find a set of exercises with problems for you to practice. In the
middle and at the end of each chapter, you will find a set of review problems. After chapter 2, 4 and 6,
you will find cumulative review problems.
Thanks to Alberta Latorre, every chapter has a Chapter Summary at the end that will summarize the
major topics of each section.
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CHAPTER 1: INTEGERS
CHAPTER 1 CONTENTS
1.1 Introduction to Integers
1.2 Absolute Value
1.3 Addition of Integers
1.4 Subtraction of Integers
1.5 Multiplication and Division of Integers
1.6 Exponents and Roots
1.7 Order of Operations
Image from www.misterteacher.com
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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1.1 Introduction to Integers
There once was a line full of numbers
That never did sleep nor did slumber
There are many good reasons
To compute in all seasons
In Fall, Winter, Spring, and the Summer
This little known limerick by an even lesser known
mathematician-poet is convincing proof that everyone
should learn mathematics. Even if your dreams of being
an artist – a writer, a singer, a painter, an actor – are
slow to materialize in the waking world, mathematical
skills are valuable in the present and in the future, at
home and for so many different jobs and careers. In
fact, the author of the limerick pays the bills with his
mathematical skills, while still having the time to
explore many different avenues of artistic creativity.
A good “number sense,” as it is called, is the very
foundation for understanding mathematics. However,
some students feel that they are allergic to math and that
working with integers (also called signed numbers) will
send them into mathematical sneezing fits.
So, in this chapter, when we perform arithmetic with
integers, we will look at a few different strategies. I am
confident that at least one of the strategies will make
“sense” to you!
Image from Microsoft Office Clip Art
Images from Microsoft Office Clip Art
Image from Microsoft Office Clip Art
3 -2
4
-1
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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Soon you will learn to perform operations on integers. This means that you will learn to add,
subtract, multiply, and divide integers. But first, you should understand what integers are.
So, let’s begin by defining the integers as well as other kinds of numbers used in math.
Numbers can be classified into different groups (number systems). Three number systems are
described in the following chart.
NUMBER SYSTEMS
Natural
Numbers
The natural numbers are also called the counting numbers.
The natural numbers are {1, 2, 3, 4, 5, . . . }.
Look at the natural numbers on the number line below.
Note: There is no greatest or “last” natural number. The arrow on the number
line indicates that the numbers continue on endlessly.
Whole
Numbers
The whole numbers include the set of natural numbers and the number 0.
The whole numbers are {0, 1, 2, 3, 4, 5, . . . }.
Look at the whole numbers on the number line below and notice that the number 0
is included.
Note: There is no greatest or “last” whole number. The arrow on the number
line indicates that the numbers continue on endlessly.
Integers
The integers are the positive and negative counting numbers and the number 0.
The integers are { … , -5 , -4 , -3 , -2 , -1 , 0 , 1 , 2 , 3 , 4 , 5, … }.
Look at the integers on the number line below.
Note: There is no least or “first” integer and there is no greatest or “last” integer.
The arrows on the number line indicate that the numbers continue on endlessly.
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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Practice 1: Circle each number system that the given number belongs to, and cross out each
number system that the given number does not belong to.
a. 7 Natural numbers Whole numbers Integers
b. – 5 Natural numbers Whole numbers Integers
c. – 2 Natural numbers Whole numbers Integers
d. 0 Natural numbers Whole numbers Integers
Answer:
a. 7 Natural numbers Whole numbers Integers
b. – 5 Natural numbers Whole numbers Integers
c. – 2 Natural numbers Whole numbers Integers
d. 0 Natural numbers Whole numbers Integers
Watch it: http://youtu.be/-t-vLNULus8
(To view video links in another window, press the control key as you click the link.)
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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POSITIVE AND NEGATIVE INTEGERS
The set of integers can be categorized into three distinct groups (subsets):
Positive Integers {1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , … }
Zero { 0 }
Negative Integers {… , -11 , -10 , -9 , -8 , -7 , -6 , -5 , -4 , -3 , -2 , -1}
Look at these subsets on the number line below.
Imagine yourself standing at the number 0, holding a gift card that you received for your
birthday. The gift card allows you to take 5 free steps, but it’s up to you to decide whether to
take those steps to the right or to the left.
If you start at 0 and take 5 steps to the right, you will arrive at positive 5, written simply as 5.
If you start at 0 and take 5 steps to the left, then you will arrive at negative 5, written as –5.
negative integers positive integers zero
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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Practice 2: Place each of the following numbers on the number line. (For a frame of
reference, the numbers 0 and 1 are given.)
Write these numbers on the number line: 2 5 3 1 6 6
Answer:
Watch it: http://youtu.be/_T8xuW0joNY
Practice 3: What is the value of each of the capital letters? (For a frame of reference, the
numbers 0 and –6 are given.)
A = B = C = D = E = F =
Answer: A = -4 B =5 C = -2 D = 2 E = 6 F = -5
Watch it: http://youtu.be/Abo1iiqwsm4
0 1
0
A B C D E F
– 6
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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Real Numbers Before we continue our study of integers, we should point out that the number line is a densely
populated line. The integers are few and far between, mathematically speaking. There are many
more numbers on the number line than just the integers. For instance, there are fractions and
decimals. Look at the location of some fractions and decimals on the number line below.
The fractions and decimals belong to a number system called the Rational Numbers. You will
study these numbers in Chapter 3 and Chapter 4 of this book. You will study other non-integers
in future math courses. So, to help you become familiar with the various kinds of numbers used
in mathematics, an overview of the number systems is presented below in diagram form. The
diagram describes each number system and allows you to see the relationships among them.
Strangely Beautiful Fact: If you pick any real number (integer, fraction, decimal) on the number
line, there is no real number “right next to it” on either side. That is, there is no closest real
number either to the right or the left. There are also no gaps or holes in the number line. Strange.
Beautiful. Fact. This is why mathematicians say that the real number line is a continuum.
Watch All: http://youtu.be/c_SqQTq78sg
REAL NUMBERS
All #'s on number line
RATIONAL NUMBERS
#'s that can be expressed as below
INTEGERS
{ ..., -3, -2, -1, 0, 1, 2, 3, ...}
OPPOSITES OF NATURAL NUMBERS
{ ..., -3, -2, -1}
WHOLE NUMBERS
{ 0, 1, 2, 3, ...}
ZERO
0
NATURAL NUMBERS
{ 1, 2, 3, ...}
FRACTIONS
1/2 -5/8
DECIMALS
decimals that end or repeat a pattern
-8.65 2.575757...
IRRATIONAL NUMBERS
decimals that do not end or repeat a pattern
7.45182453... π
-1.75 ¾ -3½
2.5
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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1.1 Introduction to Integers Exercises
1. Name each set of numbers shown below.
{0, 1, 2, 3, 4, 5, . . . }
{1, 2, 3, 4, 5, . . . }
{ … , -5 , -4 , -3 , -2 , -1 , 0 , 1 , 2 , 3 , 4 , 5, … }
2. Circle each number system that the given number belongs to, and cross out each number
system that the given number does not belong to. (The first number is done for you.)
3. Place each of the following numbers on the number line. The number 0 is already shown.
1 –5 3 –2 7 –4
4. What is the value of each of the points named by the capital letters on the number line?
(For a frame of reference, the number 0 is given.)
A = B = C = D = E = F =
- 3 belongs to the natural numbers whole numbers integers
1 belongs to the natural numbers whole numbers integers
4 belongs to the natural numbers whole numbers integers
0 belongs to the natural numbers whole numbers integers
- 1 belongs to the natural numbers whole numbers integers
0 6
0
A B C D E F
– 6
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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5. Circle all the integers in the list of numbers below.
1 5 3
7, 6, 0.4, , 9, 0, 1.8, 4, 3 ,2 8 4
6. Circle all the positive integers in the list of numbers below.
5 17, 6.2, 0.4, , , 0, 8, 4.3, 3,
2 7
7. Circle all the negative integers in the list of numbers below.
5 2 1 35.9, , , , , 0, .6, 4 , ,
9 5 2 4
CCBC Math 081 Introduction to Integers Section 1.1 Third Edition 10 pages
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1.1 Introduction to Integers Exercises Answers
1. Whole Numbers
Natural Numbers (or Counting Numbers)
Integers
2.
3.
4. A 3 B 4 C 1 D 2 E 5 F 4
5.
6.
7.
- 3 belongs to the natural numbers whole numbers integers
1 belongs to the natural numbers whole numbers integers
4 belongs to the natural numbers whole numbers integers
0 belongs to the natural numbers whole numbers integers
-1 belongs to the natural numbers whole numbers integers
0 -4 3 -2 1 7 -5