1. Pp. 56 – 57 #1-23 Pp.52 – 53 #16-46 Pp.57 – 58 #25-31, 37-48 Chapter 1 Classwork Review P.61 evens

2. 9-19-12 Please start working on Bellwork 13. Also, homework, red pen, pencil, and book on desk.

3. 2-1 PROPERTIES OF Numbers p.64

4. 2-1 PROPERTIES OF MATHEMATICS p.64 Commutative: the order in addition and multiplication does not matter. Example: 4 + 3 = 3 + 4 9 x 5 = 5 x 9

5. Properties Associative: the grouping symbols can be shifted in addition or multiplication without changing the answer. Examples: (2 + 6) + 4 = 2 + (6 + 4) (9 x 4)5 = 9(4 x 5)

6. Properties Identity property of addition and multiplication: Example: 6 + 0 = 67 x 1 = 7

7. Name each property a.5· 7 = 7 x 5 b.c· 1 = c c.7 + a = a + 7 d.5(xy) = (5x)y Commutative Property of Multiplication Identity Property of Multiplication Commutative Property of Addition Associative Property of Multiplication

8. Try This Name each property a.3 + 6 = 6 + 3 b.8 = 1 x 8 c.(3z)m = 3(zm) Commutative Property of Addition Identity Property of Multiplication Associative Property of Multiplication

9. Using Properties and Mental Math Example Use mental math to simplify 42 + 53 + 8 + 67 + 7 + 3 By using the comm. property of addition, we can rewrite the problem as 42 + 8 + 53 + 7 + 67 + 3 50 + 60 + 70 = 180

10. Try This 1. 6 + 27 + 14 6 + 14 + 27 = 47 2. 8 + 0 + 2 + (-7) 8 + 2 + (-7) 10 + (-7) = 3 3. 5 + 12 + 18 + 5 5 + 5 + 12 + 18 10 + 30 = 40

11. Using Properties and Mental Math Example Use mental math to simplify 4· (5· 9) By using the assoc. property of multiplication, we can rewrite the problem as (4· 5) · 9 20· 9 = 180

12. Try This 1. 25· (4· 3) (25· 4)· 3 100· 3 = 300 (2· 15)· (-8) 30· (-8) = -240 2. 2· [15· (-8)]

13. Agenda 9-19-12 P.67 #18-38 even