Warm Up

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Preview
Warm Up
California Standards
Lesson Presentation
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Warm Up Add or subtract. 1. 2.5 3.7 2. 3.
Multiply or divide. 4. 5. 0.03(4.8) 6.
12 1.5
1.2
1920
12
6
0.144
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Vocabulary
Commutative Property Associative
Property Distributive Property
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Additional Example 1 Identifying Properties of
Addition and Multiplication Name the property
that is illustrated in each equation. A. (4) ? 9
9 ? (4) B.
(4) ? 9 9 ? (4)
The order of the numbers changed.
Commutative Property of Multiplication
The factors are grouped differently.
Associative Property of Addition
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Check It Out! Example 1 Name the property that is
illustrated in each equation. A. (13)2
2(13) B. (18 4) 6 18 (4 6)
The order of the numbers changed.
(13)2 2(13)
Commutative Property of Multiplication
The factors are grouped differently.
(18 4) 6 18 (4 6)
Associative Property of Addition
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Additional Example 2A Using the Commutative and
Associate Properties Simplify each expression.
Justify each step. 29 37 1
Commutative Property of Addition
29 37 1 29 1 37
Associative Property of Addition
(29 1) 37
30 37
Add.
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Additional Example 2B Using the Commutative and
Associate Properties Simplify each expression.
Justify each step. 7 ? ?
2 9
1 7
Commutative Property of Multiplication
Associative Property of Multiplication
Multiply.
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Check It Out! Example 2A Simplify each
expression. Justify each step. 13 14 7
Commutative Property of Addition
13 14 7 13 7 14
Associative Property of Addition
(13 7) 14
20 14
Add.
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Check It Out! Example 2B Simplify each
expression. Justify each step. 4 ? 3 ?
1 4
Commutative Property of Multiplication
Associative Property of Multiplication
Multiply.
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The Distributive Property is also helpful when
you do math mentally. When you need to find the
product of two numbers, write one of the numbers
as a sum or difference. Then use the Distributive
Property to help you find the product mentally.
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Additional Example 3A Using the Distributive
Property Write each product using the
Distributive Property. Then simplify. 9(31)
9(31) 9(30 1)
Rewrite 31 as a sum.
(9 ? 30) (9 ? 1)
Distributive Property
270 9
Multiply.
279
Add.
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Additional Example 3B Using the Distributive
Property Write each product using the
Distributive Property. Then simplify. 8(59)
8(59) 8(60 1)
Rewrite 59 as a difference.
(8 ? 60) (8 ? 1)
Distributive Property
480 8
Multiply.
472
Subtract.
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Check It Out! Example 3A Write each product
using the Distributive Property. Then
simplify. 8(19)
8(19) 8(10 9)
Rewrite 19 as a sum.
(8 ? 10) (8 ? 9)
Distributive Property
80 72
Multiply.
152
Add.
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Check It Out! Example 3B Write each product
using the Distributive Property. Then
simplify. 5(48)
Rewrite 48 as a difference.
5(48) 5(50 2)
(5 ? 50) (5 ? 2)
Distributive Property
250 10
Multiply.
240
Subtract.
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Lesson Quiz
Name the property that is illustrated in each
equation. 1. (3 1) 2 3 (1 2) 2. 6 ? y
? 7 6 ? 7 ? y Simplify the expression. Justify
each step. 3. Write each product using the
Distributive Property. Then simplify 4. 4(98) 5.
7(32)
Associative Property of Add.
Commutative Property of Multiplication
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392
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