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

Please start working on Bellwork 13. Also, homework, red pen, pencil, and book on desk.

2-1 PROPERTIES OF Numbers p.64

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

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)

Properties Identity property of addition and multiplication: Example: = 67 x 1 = 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

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

Using Properties and Mental Math Example Use mental math to simplify By using the comm. property of addition, we can rewrite the problem as = 180

Try This = (-7) (-7) 10 + (-7) = = 40

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

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

Agenda P.67 #18-38 even