1. Adding Integers
Chp 2.2

2. Let’s add
= 132
= 120
670
Adding is just like we have always added…when the numbers are positive.
What about with different signs?

3. Adding Integers
To add integers with the same sign, we take their absolute value
If both integers are positive, the answer is positive.
If both integers are negative, the answer is negative.
|-49| = 49 and the |-23|= 23, so = 72, BUT both integers are negative so the sum is -72.
|190| = 190 and |76| = 76, so = Both of the integers were positive, so the sum is positive.

4. Adding Integers
To add integers with different signs, we subtract the absolute values.
The sum is positive, IF the positive integer’s absolute value is greater.
The sum is negative, IF the negative integer’s absolute value is greater.
|-45|= 45 and |7| = 7, so 45 – 7 = absolute value is larger than 7 absolute value, so the sum is negative = -38
|-14| = 14 and |22| = 22 so 22 – 14 = absolute value is larger than -14 absolute value so the sum in positive = 8

5. Adding Integers
To extend this concept to 3 or more terms, you work through the problem taking two terms at a time.
|-7| = 7 and |20| = 20, so 20 – 7 = 13. The absolute value of 20 is larger than the absolute value of -7 so the sum is positive = 13.
So, now take this result and work with the next term.
|13| = 13 and |-11| = 11, so 13 – 11 = 2. The result is ?
Positive! The absolute value of 13 is larger than absolute value of is positive, so the sum is positive.
= 2