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Comparing Integers
BEFORE
Now
WHY?
You compared and ordered
fractions and decimals.
You’ll compare and order
integers.
So you can order temperatures, as
in Exercise 34.
In the Real World
Word Watch
integer, p. 533
positive integer, p. 533
negative integer, p. 533
opposites, p. 534
Space Shuttles During a countdown for a
shuttle launch, “T10 seconds” means
10 seconds after liftoff. What number
represents “T10 seconds”?
During a launch, each second can be
assigned an integer. The following
numbers are integers .
. . . , 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, . . .
Negative integers are integers that are less than 0. Positive integers
are integers that are greater than 0. Zero is neither negative nor positive.
Negative numbers
6
5 4 3 2 1
Positive numbers
0
1
2
3
4
5
6
The integer 5 is read “negative 5.”
Integers are often used to represent real-world quantities. Words like
profit, increase, and above often indicate a positive integer. Words like
loss, decrease, and below indicate a negative integer.
EXAMPLE
1
Using Integers
Write the integer that represents the situation.
a. The countdown for the space shuttle is at “T10 seconds.”
ANSWER 10 seconds
b. A withdrawal of $25
ANSWER $25
Your turn now
1. a $15 profit
Write the integer that represents the situation.
2. a 9 point decrease
Lesson 11.1
3. a loss of 5 yards
Comparing Integers
533
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Opposites Numbers increase as you move from left to right on a
number line. Two numbers are opposites if they are the same distance
from 0 on a number line, but are on opposite sides of 0.
EXAMPLE
with
2
Identifying Opposites
Find the opposite of 3.
Reading
The integer 3 is read
as “negative 3” or as
“the opposite of 3.”
3 units
3
2
3 units
1
0
1
2
3
ANSWER The opposite of 3 is 3.
EXAMPLE
3
Comparing Integers
Compare 8 and 5.
8
9
5
8
7
6
5
4
3
2
1
0
1
ANSWER Because 8 is to the left of 5 on the number line, 8 5.
Your turn now
Find the opposite of the integer.
5. 7
4. 8
6. 12
7. 0
Copy and complete the statement using < or >.
8. 2 _?_ 2
EXAMPLE
4
9. 0 _?_ 1
10. 4 _?_ 5
11. 8 _?_ 9
Ordering Integers
Golf In a golf tournament, the player with
the lowest score wins. The table shows the
scores of several golfers (including the
winner) in the 2001 Masters. Who won?
Solution
16 14
20 16 12 8
5
4
0
4
0
4
Golfer
David Duvall
Shingo Katayama
Jesper Parnevik
Duffy Waldorf
Tiger Woods
Score
14
4
5
0
16
8
ANSWER Tiger Woods won the 2001 Masters with the lowest score of 16.
534
Chapter 11
Integers
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INTERNET
Exercises
eWorkbook Plus
CLASSZONE.COM
More Practice, p. 718
Getting Ready to Practice
Vocabulary Find the opposite of the integer.
2. 1
1. 9
3. 15
Copy and complete the statement using < or >.
4. 7 _?_ 0
5. 2 _?_ 6
6. 8 _?_ 9
Graph the integers on a number line. Then order the integers from
least to greatest.
7. 3, 2, 7, 9, 0
8. 2, 5, 6, 10, 8
9. 9, 0, 2, 3, 5
10. Scuba Divers A scuba diver is 12 feet below sea level. A second scuba
diver is 25 feet below sea level. Write integers to represent the divers’
positions relative to sea level.
Practice and Problem Solving
Write the integer that represents the situation.
11. 6 degrees below 0
12. an increase of 20 cm
13. 5 people join the Math Club
14. a loss of $3
15. a withdrawal of 25 dollars
16. 2 feet under water
17. In-line Skating In-line skates are on sale for $10 off, helmets are $5 off,
and knee pads are $4 off. Use an integer to represent the change in
price for each item.
Find the opposite of the integer.
with
Example
1
2
3
4
Homework
Exercises
11–17
18–21
22–29
30–34
Online Resources
CLASSZONE.COM
• More Examples
• eTutorial Plus
18. 4
19. 8
20. 11
21. 0
Copy and complete the statement using < or >.
22. 3 _?_ 7
23. 6 _?_ 0
24. 0 _?_ 4
25. 5 _?_ 7
26. 9 _?_ 9
27. 1 _?_ 5
28. 11 _?_ 12
29. 10 _?_ 8
Order the integers from least to greatest.
30. 8, 2, 6, 7, 3
31. 8, 0, 5, 1, 1
32. 1, 4, 4, 9, 6
33. 0, 3, 9, 6, 6
Lesson 11.1
Comparing Integers
535
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34. Temperatures The table shows the average low temperature for each
month in Big Delta, Alaska. Order the temperatures from least to
greatest. Which month has the lowest average low temperature?
Average Low Temperatures in Big Delta, Alaska
Month Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec.
F
11 6 3
21 37 47 51 46 36 18 2 9
Number Sense Tell whether the statement is true or false.
35. The opposite of five is greater than negative four.
36. Zero is greater than negative seven.
37. The opposite of negative nine is less than ten.
38. Writing A number is sometimes less than its opposite. Use examples to
explain this statement.
39. Challenge Two integers are opposites of each other. One integer is
7 units to the right of 5 on a number line. What are the two integers?
Mixed Review
Use a number line to add the numbers. (p. 688)
40. 5 4
41. 12 3
42. 8 2
Classify the solid. (Lesson 10.5)
43.
44.
45.
Basic Skills Evaluate the expression when x 4.5 and y 1.23.
46. 6.07 x
47. x 2.58
48. y 10.9
Test-Taking Practice
49. Multiple Choice A 2-degree increase in temperature is represented by
INTERNET
which of the following?
State Test Practice
CLASSZONE.COM
A. 20
B. 2
C. 2
D. 20
50. Multiple Choice If the integers 12, 4, 11, 12, 6, and 7 are put in
order from least to greatest, which integer will be third in the list?
F. 12
536
Chapter 11
Integers
G. 4
H. 6
I. 12