1'7 The Commutative and Associative Properties

1
1.7 The Commutative and Associative Properties

• Chapter test next Wednesday 9/20/06
• Read Pages 32-33
• Math 7 (9-22, 26-28)
• Prealgebra (11-18, 21-23, 24, 25-28)

2
Commutative Property

• of Addition
• Algebraic xyyx
• Arithmetic 2442
• In words In a sum, you can add the terms in any
  order.

• of Multiplication
• Algebraic xyyx
• Arithmetic
• In words In a product, you can multiply factors
  in any order.

3
Association Property

• Of addition
• Algebraic (cd)ec(de)
• Arithmetic
• (12)31(23)
• In words Changing the grouping of terms will not
  change the sum.

• Of Multiplication
• Algebraic
• CUUC
• Arithmetic
• In words Changing the grouping of factors will
  not change the product.

4
Explain Why it doesnt matter which number you
use as length when you find the perimeter of the
recangle.

• P2w2l
• Is P2l2w?
• Raise your hand if you say yes?
• Raise your hand if you say no?

w
l
5
Show that

• (12)3(6)6
• 3636 yes

6
Solve using Mental math

• (2938)71
• (2971)38
• (100)38
• 138

7
Lets do the matching on page 34 (5-8)