Transcript 2_1 NumberLine and absolute valueTROUT10

Chapter 2
Integers and Rational Numbers
(take out chapter 1 from your notebook and
leave ch1 stuff at home in a folder to study
off of for star test and final project)
2.1 Integers and the Number Line
• Objectives:
1. To give an integer that corresponds to a
real-world situation
2. To compare integers using < and >
3. To find the absolute value of a number
Integers
•Any number such as
. . . –4, -3, -2, -1, 0, 1, 2, 3, 4 . . .
•Positive Integers are greater than zero.
•Negative Integers are less than zero.
•“Zero” is neither positive or negative.
Number Line
-6
-4
-2
0
2
4
6
Two numbers are OPPOSITES of
one another if they are the same
distance from zero but in opposite
directions.
-6
-4
-2
0
2
4
6
6 and -6 are opposites.
4 and -4 are opposites
-6
-4
-2
0
2
4
6
Absolute Value: The number of
units a number is from zero on the
number line. (Always Positive)
-6
-4
-2
0
2
|-4| = 4
4
6
Absolute Value: (Always Positive)
-6
-4
-2
0
2
|6| = 6
4
6
Find the Opposite and the Absolute
Values of -7
-6
-4
-2
0
2
4
6
Find the Opposite and the Absolute
Values of -7
7 units
-6
-4
7 units
-2
0
2
4
Opposite of –7 is 7
6
Find the Opposite and the Absolute
Values of -7
|-7| = 7
7 units
-6
-4
-2
0
2
4
6
Evaluating Absolute Value
Before you evaluate find the absolute value of
the number then do the operation
Example:
-5 + 4 =
5+4=9
Example: Evaluate
t – 15 for t = -36
= -36 -15
=36-15
=21
Write an integer that means “a
profit of $4
+4
Write an integer that means “12
yards gained”
+12
Write an integer that means “a
loss of 73 points on the
NASDAQ”
-73
Write an integer that means
“losing 11 pounds on a diet”
-11
On a number line, values
INCREASE as you go RIGHT
-6
-4
-2
0
2
4
6
Big Number > Little #
Or
• Little # <
Big Number
True or False?
-5 < 7
-6
-4
-2
0
True
2
4
6
True or False?
-6 < -2
-6
-4
-2
0
True
2
4
6
True or False?
6 < 0
-6
-4
-2
0
2
False
4
6
True or False?
-6 > 5
-6
-4
-2
0
2
False
4
6
Write the integers –4, 5, 3,
-2, and 0 from least the
greatest.
-6
-4
-2
0
2
4
-4, -2, 0, 3, 5
6
The Number Line Dance
Homework
• Page 57 (2-54) even
Remember to write the
problem!!