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 situation2. 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

0 42-6 -4 -2 6

Two numbers are OPPOSITES of one another if they are the same

distance from zero but in opposite directions.

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6 and -6 are opposites.

4 and -4 are opposites

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Absolute Value: The number of units a number is from zero on the number line. (Always Positive)

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|-4| = 4

Absolute Value: (Always Positive)

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|6| = 6

Find the Opposite and the Absolute Values of -7

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Find the Opposite and the Absolute Values of -7

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Opposite of –7 is 7

7 units 7 units

Find the Opposite and the Absolute Values of -7

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|-7| = 7

7 units

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 INCREASEINCREASE as you go RIGHTRIGHT

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Big Number Big Number >> Little #Little #

Or

• Little # Little # < < Big NumberBig Number

True or False?-5 < 7

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True

True or False?-6 < -2

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True

True or False?6 < 0

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False

True or False?-6 > 5

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False

Write the integers –4, 5, 3, -2, and 0 from least the

greatest.

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-4, -2, 0, 3, 5

The Number Line Dance

Homework

• Page 57 (2-54) even

Remember to write the problem!!