1. 2-1 Integers
Pg.76

2. Essential Question
When would you need to use negative integers in the real world?

3. Definitions
integers- the set of whole numbers and their opposites (positive or negative)
opposite- two numbers that are an equal distance from zero on a number line
absolute value- the distance of a number from zero on a number line; shown by l l

4. INTRODUCTION TO INTEGERS
Integers are positive and negative numbers.
…, -6, -5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5, +6, …
Each negative number is paired with a positive number the same distance from 0 on a number line. These numbers are called opposites. -3 -2 -1 1 2 3

5. Integers Numbers to the left of zero
are less than zero.
Numbers to the right of zero are more than zero.
The numbers –1, -2, -3 are called negative integers. The number negative 3 is written –3.
The numbers 1, 2, 3 are called positive integers. The number positive 4 is written +4 or 4.
Zero is neither negative nor positive.

6. Negative numbers are used to…1. 2. 3.
The answers are on the next 3 slides 

7. Negative Numbers Are Used to Measure Temperature

8. Negative Numbers Are Used to Measure Under Sea Level30 20 10
-10
-20
-30
-40
-50

9. Negative Numbers Are Used to Show Debt
Let’s say your parents bought a car but
had to get a loan from the bank for $5,000.
When counting all their money they add
in -$5.000 to show they still owe the bank.

10. Hint
If you don’t see a negative or positive sign in front of a number it is positive.
9 = 9 +

11. Opposite Example 1
The opposite of a number is the same distance from 0 on a number line as the original number, but on the other side of 0.
Zero is its own opposite.
–4 and 4 are opposites –4 4 • •
–5–4–3–2–1 0

12. Opposite Example 2
Graph the integer -7 and its opposite on a number line.
7 units units
–7–6–5–4–3–2–1 0

13. Graph the integer and its opposite on a number line.
Opposite Examples 3&4
Graph the integer and its opposite on a number line.
-9–8 –7–6–5–4 –3–2 –1 0
–8 –7–6–5–4 –3–2 –1 0

14. Absolute Value Video Clip (1:30)
Write down 1 fact from the clip about absolute value.

15. The symbol is read as “the absolute value of
The symbol is read as “the absolute value of.” For example -3 is the absolute value of -3.
Reading Math

16. Absolute Value Example 1
Use a number line to find each absolute value.
|8|
8 units
–8 –7–6–5–4 –3–2 –1 0
8 is 8 units from 0, so |8| = 8.

17. Absolute Value Example 2
Use a number line to find each absolute value.
|–12|
12 units
–12 –11 –10 –9 –8 –7 –6 –5 –4 –3 –2 –
–12 is 12 units from 0, so |–12| = 12.

18. Absolute Value Examples 3 & 42
–8 –7–6–5–4 –3–2 –1 0 7
–8 –7–6–5–4 –3–2 –1 0

19. You can compare and order integers by graphing them on a number line.
Integers increase in value as you move to the right along a number line.
They decrease in value as you move to the left.
The symbol < means “is less than,” and the symbol > means “is greater than.”
Remember!

20. Comparing Example 1 Compare the integers. Use < or >. >
>
-4 is farther to the right than -11, so -4 > -11.

21. Comparing Example 2
Use a number line to order the integers from least to greatest.
–3, 6, –5, 2, 0, –8
–8 –7–6 –5–4 –3 –2 –1 0
The numbers in order from least to greatest are –8, –5, –3, 0, 2, and 6.

22. Comparing Examples 3&4 › ‹ ‹

23. Comparing Example 5
–8 –7–6–5–4 –3–2 –1 0

24. Work Session-Together
Showing off Integer WS
Meaning of Integer WS
Comparing and Ordering Sort
Number Line WS
Work Session-With your Partner
Work Session- On your own

25. Closing When would you use negative numbers in the real world?
Do the numbers increase or decrease as you move to the left of zero?
< means:
> means:

26. Homework
13.3 WS Comparing and Ordering Integers

27. Role of Integers Video Clip
Write down 3 facts about integers from the clip. 1. 2. 3.

28. Homework
Workbook
pg. 13
All problems

29. Work Session
Textbook
Pg. 78
16-38 even only
GRADED