September 22, 2008
PRE-ALGEBRA A
1.7 COMMUTATIVE AND ASSOCIATIVE
PROPERTIES (PG. 32)
PURPOSE: Students will be able to
simplify expressions by applying the
associative and commutative properties.
CA STANDARDS: AF 1.3
COMMUTATIVE PROPERTY OF
ADDITION AND MULTIPLICATION
Compare the question. Any similarities or
differences? Solve the question.
A) 27+11+73
B) 27+73 +11
C) 5(29)(2)
D) 5(2)(29)
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September 22, 2008
COMMUTATIVE PROPERTY OF ADDITION:
You can add the numbers in any order.
Example: 88+65+35 = 65+35+88
COMMUTATIVE PROPERTY OF
MULTIPLICATION: You can multiply the
numbers in any order.
Example: 5(8)(2)= 2(5)(8)
ASSOCIATIVE PROPERTY OF
ADDITION AND MULTIPLICATION
Compare the questions. Any similarities
or differences? Solve the questions.
E) (2+17)+3
F) 2 + (17+3)
G) (9 • 4) • 5
H) 9 • (4 • 5)
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September 22, 2008
ASSOCIATIVE PROPERTY OF ADDITION:
You change the grouping of numbers
without changing the sum.
Example: (13+8)+25 = 13+(8+25)
ASSOCIATIVE PROPERTY OF
MULTIPLICATION: You change the
grouping of numbers without changing
the product.
Example: (5 • 10) • 3 = 5 • (10 • 3)
Identify the property.
1) 3 • (8 • 4) = (3 • 8) • 4
2) 4 + 7 = 7 + 4
Associative Prop. of
Multiplication
Commutative Prop. of Addition
Associative Prop. of
Addition
Commutative Prop. of Multiplication
3) 8 + (9 + 7) = (8 + 9) + 7
4) 3 • 8 = 8 • 3
5) 21 + 9 = 9 + 21
Commutative Prop. of Addition
6) (25 • 10) • 10 = 25 • (10 • 10) Associative Prop.
of Multiplication
7) (6 + 9) + 11 = 6 + (9 + 11) Associative Prop. of
Addition
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September 22, 2008
Use the commutative and associative property to find
the missing number.
8) 25 • (15 • 4) = ( ___ • 15) • 4
9) 2 + 8 = 8 + ___
10) ( ___ + 19) + 11 = 37 + (19 + 11)
11) 9 • ___ = 11 • 9
EXIT SLIP 1.7
Name the property illustrated by the
statement.
1) 8 + 12 = 12 + 8
2) (9 • 10) • 2 = 9 • (10 • 2)
3) 5 • 10 = 10 • 5
4) 7 + (12 + 8) = (7 + 12) + 8
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September 22, 2008
HOMEWORK
A22: TB PG. 34-35 #9-12,
15-19, 21, 22, 27, 28
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