1. Adding and Subtracting Positive and Negative Numbers
Chapter 1
Section 1.2

2. Objective
Students will add real numbers using rules for addition. Students will also subtract real numbers and simplify expressions involving differences.

3. Concept Rules for addition:
If you have same signs, add together, keep the sign you start with.
If you have opposite signs, subtract big number minus small number, keep sign from larger number you start with.

4. Concept Rules for addition:
If your numbers are opposites, your answer is always 0.

5. Example
Simplify (-2) 8 + (-5) (-9) (-2)

6. Example
Simplify
7 + (-9) (-12)
10 + (-11) (-13) + 14

7. Example
Simplify 1. 3x (-4x) + (-22)

8. Concept
Rules for subtraction: For all real numbers a and b, the difference a-b is defined by a – b = a + (-b) To subtract b, add the opposite of b

9. Example
Simplify 3 – – 1 -4 – (-10) 9 – 12 3 – (-4) -6 – (-10)

10. Example
Simplify
y – (y + 6)
-30 decreased by -19

11. Questions

12. Assignment
Worksheet