1. Introduction to Integers; Signed Numbers
Section 2.1
Introduction to Integers; Signed Numbers

2. Number Line

3. Example
Graph the numbers 0, -7, 9, 12, -20

4. Inequalities A symbol used to compare numbers < less than
> greater than

5. Examples
Place the inequality
0 -1

6. Absolute Value
Finds the distance between the given number and the origin (0). The symbol is | |.
|x| = x
|-x| = x

7. Examples Simplify the expression | -15 | | -27 | | 12 | | 15 |
| 12 |
| 15 |
- | -22 |
- | 87 |

8. Opposite Numbers Changing the sign of the given number.
The opposite of x is -x
The opposite of –x is x

9. Examples Find the opposite of 34 Find the opposite of 85

10. Multiple Negatives
Given a value with an even number of negatives will result in a positive sign.
Double negatives = positive
Given a value with an odd number of negatives will result in a negative sign.

11. Example
Simplify
---95
--34
- ( - ( - ( - 45 ) ) )
- ( - ( - 98 ) )

12. Order
Increasing Order : Writing the numbers from lowest number to highest number.
Decreasing Order : Writing the numbers from highest number to lowest number.

13. Example
Given these numbers, write them in increasing order -88, 254, 12, -16, 55

14. Example
Given these numbers, write them in decreasing order 12, 85, -54, 9, -2