Chapter 4 Section 2

I Can . . .

Evaluate and Simplify Powers

Use Order of Operations with Exponents

HW: 4-2 Ws and pg 180 #11 – 27 ODD SHOW WORK

Powers

26 Means 2 • 2 • 2 • 2 • 2 • 2

Whole Expression is called a Power.

Base: The number used in multiplication

Exponent: The number of repeatedmultiplications

Power Verbal Expression Value 121 Twelve to the first power 12 62 Six to the second power 6•6 = 36

or six squared

(0.2)3 Two-tenths to the third power (.2)(.2)(.2) = 0.008 or two-tenths cubed -74 The opposite of the quantity of (-1)(7•7•7•7) = -2,401 seven to the fourth power

(-8)5 Negative eight to the fifth power (-8)(-8)(-8)(-8)(-8) = -32,768

Using an ExponentWrite the expression using an exponent. Student Practice Problems

1. (-5)(-5)(-5) (-5)3

2. -2•a•b•a•a

3. 4 • x • y • x • y 4x2y2

1. 6•6•6•6

2. 3•x•y•y•y

3. m•m•n•n

64

3xy3

m2n2

-2a3b

Simplifying a Power

Using the Power Key1. A microscope can magnify

a specimen 103 times. How many times is that?

103 = 10•10•10 = 1,000

2. Evaluate –a4b for a = 2 and b = 3.

(-1)(2)4(3) = (-1)(16)(3) = (-16)(3) = -48

Student Practice Problems

1. The ice age ended about 104 years ago. How many years ago was this?

10 = 10•10•10•10 = 10,000

2. Simplify: 2a2 if a=7.

2•72 = 2•49 = 98

Order of Operations with Exponents

1. Grouping Symbols

2. POWERS

3. Multiplication or Division Left to Right

4. Addition or Subtraction Left to Right

15 + (4 + 6)2 ÷ 5

15 + (10)2 ÷ 5

15 + 100 ÷ 5

115 ÷ 5

23

Student Practice Problems

7(w - 3)3 + zFor w = 5 and z = 6

7(5 - 3)3 + 67(2)3 + 67(8) + 656 + 6

62

(12 – 3)2 ÷ (22 – 1)

(9)2 ÷ (22 -1)(9)2 ÷ (4 – 1)

(9)2 ÷ (3)81 ÷ 3

27

Closure

Write a numerical expression with exponents.

Simplify your expression.

Hand your expression to a partner to check your work.