1. Properties of Numbers Identify each property. a. 0 + x = x
COURSE 3 LESSON 1-8
Properties of Numbers
Identify each property.
a. 0 + x = x
Identity Property of Addition
Commutative Property of
Multiplication
b. 3(–5)(8) = 3(8)(–5)
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2. Properties of Numbers Use mental math to simplify each expression.
COURSE 3 LESSON 1-8
Use mental math to simplify each expression. a
What you think
Look for numbers that are easy to add. The sum of 3.8 and 6.2 is 10.
The sum of 10 and 17 is 27. So, = 27.
Commutative Property
Why it works =
Order of operations =
Simplify.
= 27
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3. Properties of Numbers b. 89 – 67 What you think
COURSE 3 LESSON 1-8
Properties of Numbers
(continued)
b. 89 – 67
What you think
Make the problem easier. Split 89 into parts. First, do 87 – 67 which is 20.
Then add the rest of 89: = 22.
Write 89 as
Why it works
89 – 67 = (2 + 87) – 67
Associative Property
= 2 + (87 – 67)
Order of operations =
= 22
Simplify.
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