Order of Operations

Section 1.3

1.3 Order of Operations

GOAL 1Use the order of operations to evaluate algebraic expressions.

What you should learn

To solve real-life problems, such as calculating the cost of admission for a family to a state fair.

Why you should learn it

GOAL 1 USING THE ORDER OF OPERATIONS

WHAT IS THE ORDER OF OPERATIONS?

It’s the method we use to evaluate an expression involving more than one operation:

1.

2.

3.

4.

1.3 Order of Operations

Parenthesis (innermost first, work to the outermost)

Powers

Multiplication and division

Addition and subtraction

left to right

left to right

Example 1

Evaluate the expression when x = 3.

1. 2. 227 3x 24 8x 24(3) 8

4(9) 8

36 828

227 3 3

27 9 3 3 3

6

EXAMPLE 2

What happens when operations that have the same priority appear in the same expression, such as 5 – 4 +1?

Perform the operations fromleft to right!

5 – 4 + 1

1 + 1

2

5 – 4 + 1

5 – 5

0

Which is correct?

Example 2

Example 3

Example 4

24 3

5 9 2

72

5 9 2

72

14 2

72

12

6

Simplify the expression. Click to see each step.

2

24 3

5 3 2

Simplify the power.

Simplify the numerator.

Work from left to right.

Subtract.

Simplify.

Hint: The fraction bar serves as a grouping symbol. Simplify the numerator and denominator separately before the final step.

Checkpoint1. Evaluate the expression when x = 5.

a. 2x2 + 8 b. 100 ÷ x2 + 6

2. Simplify the expression.

a. 25 + 10 – 8 b. 24 ÷ 2 • 3

3. Simplify the expression.

2

16 2 8

10 2 4

58 10

27 36

4

Homework

• Worksheet 1.3 B

#’s 1-24 evensSHOW YOUR WORK!!

Can use a calculator to CHECK your answers but you MUST show your

work for each step!