1. Properties of Real Numbers

2. Properties of Addition & Multiplication: For all real #’s, a, b, c… Closure: then a+b is a real number ab is a real number Commutative: a + b = b + a ab = ba Associative: (a+b)+c = a+(b+c) (ab)c = a(bc) Identity: a + 0 = 0 + a = a a*1 = 1*a = a Inverse: a + (-a) = 0

3. Distributive Property For all real numbers a, b, and c: a(b + c) = ab + ac and (b + c)a = ba + bc)

4. State a property to justify the following statements… 6 +(-3) = (-3) + 6 3(4a+5) = 12a + 15 (x+3) + 6 = 6 + (x+ 3) -5 + 5 = 0

5. State a property to justify the following statements… 2(4 – 5) = (4- 5)2 -5 + (x + 2) = (-5 + x) + 2 4 ( 1) = 4

6. Using Properties for Mental Math A movie ticket costs $7.75. A drink costs $2.40 and popcorn is $1.25. What is the total cost?

7. Using Properties for Mental Math You buy a sandwich for $2.95, an apple for $.45, and a bottle of juice for $1.05. What is the total cost?

8. Simplify – using properties

14. Homework Worksheet