1. Pre-Algebra: Chapter 2 LEARNING GOAL
Students will understand integers and exponents by being able to do the following:
Add & Subtract Integers
Multiply & Divide Integers
Solve Equations Containing Integers
Solve Inequalities Containing Integers
Solve Exponents
Understand the Properties of Exponents
Find a Pattern in Integer Exponents
Solve Scientific Notation

2. Today’s Learning Goal Assignment
Pre-Algebra
2-1
Adding Integers
Today’s Learning Goal Assignment
Learn to add integers.

3. Insert Lesson Title Here
Pre-Algebra
2-1
Adding Integers
Insert Lesson Title Here
Lesson Quiz: Part 1
Add.
1. –7 + (– 7)
(–9) + (–2)
–14 4
Evaluate each expression for the given value of the variable.
r for r = –15
b + (–9) for b = –6 –2
–13

4. Insert Lesson Title Here
Pre-Algebra
2-1
Adding Integers
Insert Lesson Title Here
Lesson Quiz: Part 2
5. On Monday, a local dog shelter had six dogs. By Friday they had found homes for three, but took in two more. Then how many dogs were in the shelter?
5 dogs

5. Are we ready for the FAST Track?
Pre-Algebra
2-1
Adding Integers
Are we ready for the FAST Track?

6. Pre-Algebra
2-1
Adding Integers
Pre-Algebra: 2-1 HW
Page 62
#13-24 all

7. 2-1 Adding Integers Warm Up Problem of the Day Lesson Presentation
Pre-Algebra

8. 2-1 Adding Integers Warm Up Graph each number on a number line.
Pre-Algebra
2-1
Adding Integers
Warm Up
Graph each number on a number line.
Add. 41 35

9. 2-1 Adding Integers Problem of the Day
Pre-Algebra
2-1
Adding Integers
Problem of the Day
Start at (0, 0). Walk 3 blocks west and 2 blocks north. Then walk 4 blocks south and 1 block east. What are your coordinates?
(–2, –2)

10. Insert Lesson Title Here
Pre-Algebra
2-1
Adding Integers
Insert Lesson Title Here
Vocabulary
integer
opposite
absolute value

11. Pre-Algebra
2-1
Adding Integers
Integers are sets of whole numbers, including 0, and their opposites. The sum of two opposite integers is zero.
–3 and 3 are opposites
Negative integers
0 is its own opposite
Positive integers

12. Additional Example 1: Using a Number Line to Add Integers
Pre-Algebra
2-1
Adding Integers
Additional Example 1: Using a Number Line to Add Integers
Use a number line to find the sum.
(–6) + 2 –6 2
–6 –5 –4 –3 –2 –
You finish at –4, so (–6) + 2 = –4.
To add a positive number move to the right. To add a negative number move to the left.
Helpful Hint

13. 2-1 Adding Integers –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 Try This: Example 1
Pre-Algebra
2-1
Adding Integers
Try This: Example 1
Use a number line to find the sum.
(–3) + 7 –3 7
–6 –5 –4 –3 –2 –
You finish at 4, so (–3) + 7 = 4.

14. If the signs are the same. . . If the signs are different. . .
Pre-Algebra
2-1
Adding Integers
Another way to add integers is to use absolute value. The absolute value of a number is its distance from 0. The absolute value of –4, written as |–4|, is 4; and the absolute value of 5 is 5.
Adding integers
If the signs are the same. . .
If the signs are different. . .
find the sum of the absolute values. Use the same sign as the integers.
find the difference of the absolute values. Use the sign of the integer with the larger absolute value.

15. Additional Example 2A & 2B: Using Absolute Value to Add Integers
Pre-Algebra
2-1
Adding Integers
Additional Example 2A & 2B: Using Absolute Value to Add Integers
Add.
A. 1 + (–2)
1 + (–2)
Think: Find the difference of 2 and 1. –1
2 > 1; use the sign of 2.
B. (–8) + 5
(–8) + 5
Think: Find the difference of 8 and 5. –3
8 > 5; use the sign of 8.

16. Additional Example 2C: Using Absolute Value to Add Integers
Pre-Algebra
2-1
Adding Integers
Additional Example 2C: Using Absolute Value to Add Integers
Add.
C. (–2) + (–4)
(–2) + (–4)
Think: Find the sum of 2 and 4.
Same sign; use the sign of the integers. –6

17. 2-1 Adding Integers Try This: Example 2A & 2B Add. A. 3 + (–6)
Pre-Algebra
2-1
Adding Integers
Try This: Example 2A & 2B
Add.
A. 3 + (–6)
3 + (–6)
Think: Find the difference of 6 and 3. –3
6 > 3; use the sign of 6.
B. (–4) + 1
(–4) + 1
Think: Find the difference of 4 and 1. –3
4 > 1; use the sign of 4.

18. 2-1 Adding Integers Try This: Example 2C Add. C. (–6) + (–7)
Pre-Algebra
2-1
Adding Integers
Try This: Example 2C
Add.
C. (–6) + (–7)
(–6) + (–7)
Think: Find the sum of 6 and 7.
Same sign; use the sign of the integers.
–13

19. Additional Example 3: Evaluating Expressions with Integers
Pre-Algebra
2-1
Adding Integers
Additional Example 3: Evaluating Expressions with Integers
Evaluate c + 4 for c = –8.
c + 4
(–8) + 4
Replace c with –8.
Think: Find the difference of 8 and 4.
–8 + 4 = –4
8 > 4; use the sign of 8.

20. 2-1 Adding Integers Try This: Example 3 Evaluate d + 7 for d = –3.
Pre-Algebra
2-1
Adding Integers
Try This: Example 3
Evaluate d + 7 for d = –3.
d + 7
(–3) + 7
Replace d with –3.
Think: Find the difference of 7 and 3.
–3 + 7 = 4
7 > 3; use the sign of 7.

21. Additional Example 4: Application
Pre-Algebra
2-1
Adding Integers
Additional Example 4: Application
Katrina opened a new bank account. Find her account balance after the first four transactions listed below.
Deposits: $200, $20 Withdrawals: $166, $38
Use a positive sign for deposits and a negative sign for withdrawals.
(–166) + (–38)
Group integers with same signs.
( ) + (–166 + –38)
Add integers within each group.
220 + (–204)
220 > 204; use the sign of 220. 16
Katrina’s account balance after the first four transactions is $16.

22. 2-1 Adding Integers Try This: Example 4 175 + 95 + (–133) + (–65)
Pre-Algebra
2-1
Adding Integers
Try This: Example 4
Michael opened a new bank account. Find his account balance after the first four transactions listed below.
Deposits: $175, $95 Withdrawals: $133, $65
Use a positive sign for deposits and a negative sign for withdrawals.
(–133) + (–65)
Group integers with same signs.
( ) + (–133 + –65)
Add integers within each group.
270 + (–198)
270 > 198; use the sign of 270. 72
Michael’s account balance after the first four transactions is $72.