1.2 order of operations part 1

Order of Operations

Section 1.2

Pages 8-14

• In this section you use the ORDER OF OPERATIONS to evaluate operations.

• What do you remember about the order of operations?

• PEMDAS PE MD AS• (please excuse-- my dear-- aunt sally)• (Parentheses, exponents, Mult, Div, Add, Subt)

Divide.

Evaluate power.27 32 2 – 3 = 27 9 2 – 3

EXAMPLE 1

27 9 2 – 3 = 3 2 – 3

3 2 – 3 = 6 – 3 Multiply.

Evaluate expressions

Multiply and divide from left to right.STEP 3

Evaluate the expression 27 32 2 3.–

There are no grouping symbols, so go to Step 2.STEP 1

Evaluate powers.STEP 2

STEP 4Add and subtract from left to right.

6 – 3 = 3

EXAMPLE 1

Subtract.

ANSWER

The value of the expression 27 32 2 – 3 is 3.

Evaluate expressions

GUIDED PRACTICE for Example 1

Evaluate power.

There are no grouping symbols, so go to Step 2.

Evaluate powers.

STEP 2

STEP 1

1. Evaluate the expression 20 – 42

There are no Multiplication and Division symbol,so go to step 4

STEP 3

20 – 42 = 24 – 16

GUIDED PRACTICE for Example 1

STEP 4Add and subtract from left to right.

20 – 16 = 4 Subtract.

ANSWER

The value of the expression 20 – 42 = 4.

GUIDED PRACTICE for Example 1

Evaluate power.

There are no grouping symbols, so go to Step 2.

Evaluate powers.STEP 2

STEP 1

STEP 3

2. Evaluate the expression 2 32 + 4

2 32 = 2 9 + 4

2 9 + 4 = 18 + 4Multiply.

Multiply.

GUIDED PRACTICE for Example 1

STEP 4Add and subtract from left to right.

18 + 4 = 22 Add.

ANSWER

The value of the expression 2 32 + 4 is 22.

GUIDED PRACTICE for Example 1

Evaluate power.

There are no grouping symbols, so go to Step 2.

Evaluate powers.STEP 2

STEP 1

STEP 3Multiply and Divide from left to right.

Divide.

3. Evaluate the expression 32 23 + 6

32 23 + 6 = 32 8 + 6

32 8+ 6 = 4 + 6

24 – (9 + 1)

= 2[9]

EXAMPLE 2 Evaluate expressions with grouping symbols

Evaluate the expression.

a. 7(13 – 8) == 35

Subtract within parentheses.

Multiply.

b. 24 – (32 + 1) = Evaluate power.

= 24 – 10 Add within parentheses.

= 14 Subtract.

c. 2[30 – (8 + 13)] = Add within parentheses.

Subtract within brackets.

=18 Multiply.

7(5)

2[30 – 21]

EXAMPLE 3 Evaluate an algebraic expression

Evaluate the expression when x = 4.

9x3(x + 2)

Substitute 4 for x.

Add within parentheses.

1836= Multiply.

= 2 Divide.

= 9 4

3(4 + 2)

3 6 9 4

=

Standardized Test Practice

EXAMPLE 4