1. Adding Integers Absent Copy
10/1,2

2. Example 1 -2 Add: 1. 5 + (-7) 7 – 5 = 2 Solution Solution
(-7)
7 – 5 = 2
Sign of larger # is neg. so -2
Solution Solution
What is a integer?
Think of last class
Any negative or positive whole #.
What is the rule when you are adding integers w/ dif. Signs?
When we have different signs we subtract and give the sign of the larger #. -2

3. Example 2
Add:
8 – 4 = 4
Sign of larger # is Pos. so 4
Solution
What is the rule when you are adding integers w/ dif. Signs?
When we have different signs we subtract and give the sign of the larger #. 4

4. Example 3
Find the sum:
(-13)
= 21
Since the #’s both have a neg. sign we add the #’s and give the answer a neg.
-21
Solution
What is the rule when you are adding integers and the signs are the same?
When the signs are the same we keep the sign they both have add the numbers.
-21

5. Example 4 -22 Evaluate the expression and find the sum:
Why is this an Expression?
Because it does not have an = sign.
What is the first step in this problem?
To substitute -8 for r
What is the rule when adding integers and the signs are the same?
When the signs are the same we keep the sign they both have add the numbers.
Evaluate the expression and find the sum:
r for r = -8
= 22
Since the #’s both have a neg. sign we add the #’s and give the answer a neg. -22
Solution
-22

6. Example 5 4 Evaluate the expression and find the sum:
5. x + y for x = 18, y = -14
18 – 14 = 4
Sign of larger # is Pos. so 4
Solution
What is the first step in this problem?
To substitute 18 for x and -14 for y
What is the rule when adding integers and the signs are Different?
When we have different signs we subtract and give the sign of the larger #. 4

7. Change in temp. is 8 degrees
Example 6
Solve the problem:
6. The temperature gauge at the Greater Cincinnati International Airport reads 23º F. The temperature changes to 15º F. What is the change in temperature?
23 + (-15) = 8
Solution
Write and expression using 2 integers we can add to get 15º F.
Change in temp. is 8 degrees