Transcript Integers_and_Absolute_Value

Integers and
Absolute Value
Integers
Integers are the whole numbers
(0, 1, 2, 3, …)
(-1, -2, -3, …)
and their opposites
Integers are modeled on a number
line:
Negative Integers
-3
-2
-1
Positive Integers
0
1
2
3
•As you move to the right on a number line, the integers
increase in value
•As you move to the left on a number line, the integers
decrease in value
Integers
• -5 is read “negative five” NOT minus five!
• You do not need to include a + sign in front of a
positive integer.
• 2 is still just 2, not +2!
• Plotting a number on a number line means to draw a
dot at the point that represents that number
– Be sure to label your points!
• Draw a number line and plot the integers -6, -2,
and 3.
-6
-2
0
3
Absolute Value
• Absolute value is the distance from zero
on a number line.
• Because AV is a distance, it is always
positive.
– There is no such thing as a negative distance.
– If I drive 11 miles to school, I drive 11 miles
home, not -11 miles!
Absolute Value
• AV is written with two vertical lines called
absolute value signs
– Ex: │7│ or │-3│
• The absolute value of 7 (│7│) is 7,
because it is seven spaces away from
zero on a number line
• The absolute value of -3 (│-3│) is 3,
because it is three spaces away from zero
on a number line
Evaluating Absolute Value
│-17│
=17
│0│
=0
│5│
=5
│-121│
=121
Opposites
• Opposites are numbers that are the same
distance from, but on opposing sides of,
zero
• Opposites have the same absolute value
• Find the opposites of the following:
8
-11
-8
11
121
-121
0
0