Warm Up

-6 + 5 =

-7 – (-0.9) =

- (-3) =

TEST!!!!

Over the first 9 lessons on Tuesday 8/26

Lesson 8/9: Applying the Properties of Operations to Add and Subtract Rational Numbers

Objective:I can apply properties of operations as strategies to add and subtract rational numbers.

“The opposite of a sum is the sum of its opposites.”

-7 2 -5 5

7 -2 5

Exercise 1 -Give it a Team Try!

2 ⅖ = 2 + ⅖ -2 ⅖ = -2 + (-⅖)

The opposite of 2 ⅖ is - 2 ⅖ or -2 + (-⅖) !

Example 1

Exercise 2Rewrite each mixed number as the sum of two signed numbers.

Exercise 3Represent each sum as a mixed number

Definitions and Concepts“The opposite of a sum is the sum of its opposites.”

-(9 + 4) = -9 + -4

-(10 + ½) = -10 + (- ½)

Commutative Property of AdditionOrder of addition does not matter.

5 + 8 = 8 + 5

3 + -7 = -7 + 3

Associative Property of AdditionChanging the order of the grouping does not change the sum.

(2 + 5) + 8 = 2 + (5 + 8)

Example 2 – Why this comes in handy

Step 1: Change subtraction to addition

Step 2: Commutative Property of Add.

Step 3: Opposite of a sum is the sum of its opposites

Step 4: Commutative Property of Addition

Step 5: Add the fractions

Step 6-8: Apply the order of operations.

Example 3:

Exercise 1 – Remember….give it a Personal Try!

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