140 likes | 218 Views
Thursday 9/25. Block 2 Integers In Class p.60 Lesson 2.6 Powers & Exponents Examples 1-2 Homework p.62 Exercises 1-27. Warm-Up. 1. List the following integers from least to greatest: −5, −11, 4, 8, −1, 0 2. Determine the SIGN of each answer. a. −209 + (− 184)
E N D
Thursday 9/25 • Block 2 Integers In Class p.60 Lesson 2.6 Powers & Exponents Examples 1-2 Homework p.62 Exercises 1-27
Warm-Up 1. List the following integers from least to greatest: −5, −11, 4, 8, −1, 0 2. Determine the SIGN of each answer. a. −209 + (− 184) b. −88(45) c. −244 ÷ −8 d. 2065 − (−6310) −11, −5, −1, 0, 4, 8 – – + +
Lesson 2.6 Powers and Exponents Write and compute expressions with powers.
Vocabulary Power Used to express a product of a repeated factor. Powers consist of two parts, the base and the exponent. Base The repeated factor. Exponent Number of times the factor is repeated. Squared A number to the second power. Cubed A number to the third power.
Powers, Bases and Exponents Exponent Repeated Factor Base Power Expanded Form
Example 1 Write each expression as a power. a. (5)(5)(5)(5) 54 b. (−11)(−11) (−11)2 c. 7 ∙ 7 ∙ 7 ∙ 7 ∙ 7 ∙ 7 76
Power Rules for Positive and Negative Bases If the base of a power is positive, the value of the power will always be positive. If the base of a power is negative, the value of the power will be: positive if the exponent is an even number. negative if the exponent is an odd number.
Example 2 Write each power in expanded form and find its value. a. 82Expanded form: 8 8 Value: 64 b. (−1)5Expanded form: (−1)(−1)(−1)(−1)(−1) The exponent is odd so the answer will be negative. Value: −1
Example 2 Continued… Write each power in expanded form and find its value. c. −44 The expression −44 should be read “the opposite of four to the fourth power.” 44 = 256 so the opposite of 256 is −256 Value: −256
Thursday 9/25 • Block 2 Integers In Class p.60 Lesson 2.6 Powers & Exponents Examples 1-2 Homework p.62 Exercises 1-27
Exit Problems Write each expression as a power. 1. 2∙ 2 ∙ 2 ∙ 2 ∙ 2 ∙ 2 2. (−1)(−1)(−1) 3. 23 4. (−5)2 5. (−3)3 26 (-1)3 Write each power in expanded form and find the value. (2)(2)(2) = 8 (–5)(–5) = 25 (–3)(–3)(–3) = –27
Explore! Positive or Negative? Step 1 Copy the table below. Step 2 Fill in the table by writing each power in expanded form. Find the value of the power. The table has been started for you below.
Explore! Positive or Negative? Step 3 Some of the answers are positive and some answers should be negative. Do you notice any patterns that would help you determine the sign of a power just by looking at the base and the exponent? Step 4 Use your pattern to determine the SIGN of each power. You do not need to find the value. a. 8⁵ b. (−9)⁴ c. (−6)¹¹ d. (−4)⁸ e. 12² f. (−1)¹⁷ Step 5 The expressions −3² and (−3)² are not equal. Explain why the two expressions are not equal and find the value of each expression.
Communication Prompt How can you tell the sign of the value of a power without doing any computations?