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Chapter 2
Integers and
Introduction to
Variables
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall.
2.2
Introduction to Integers
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall.
Definitions
Positive Numbers: Numbers greater than 0.
Negative Numbers: Numbers that are less than 0.
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Example
A worker in a silver mine in Nevada works 1445 feet
underground. Write this as a signed number.
1445 feet underground = –1445
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Graphing Integers
EXAMPLE
Graph the following integers on a number line:
1
4, 0, 2,  3
4
-4
- 3 - 2 -1 0 1 2
3 4
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Comparing Integers
For any two numbers graphed on a number line, the
number to the right is the greater number, and the
number to the left is the smaller number. Also recall that
the symbol > means “is greater than” and the symbol <
means “is less than”.
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Example
Insert < or > between each pair of numbers to make a true
statement.
< 3
a. −6 ____
b.
7
>
0 ______ 
8
>
c. 3.6 ______
 4.2
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Absolute Value
The absolute value of a number is the number’s distance
from 0 on a number line. The symbol for absolute value is
| |.
Example: Find each absolute value.
a. 6  6
b. 8  8
2 2
c.  
3 3
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Finding the Opposite of a Number
Two numbers that are the same distance from 0 on the
number line but are on opposite sides of 0.
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Example
Find the opposite of each number.
a. 11
b. ‒8
c. 0
a. The opposite of 11 is ‒11.
b. The opposite of ‒8 is 8.
c. The opposite of 0 is 0.
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Example
Simplify.
a. −(−9) = 9
b.  15  15
c.  4  4
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Reading Bar Graphs Containing Integers
EXAMPLE
Which planet has the lowest average temperature?
Neptune
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Example
According to the bar
graph, which planet
has the third lowest
average temperature?
The bar with the
third lowest
temperature is Saturn
with a lowest average
temperature of 218 F.
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