Unit 2 Exponents. NAME: CLASS: TEACHER: Ms. Schmidt _

Transcription

1 Unit 2 Exponents NAME: CLASS: TEACHER: Ms. Schmidt _

2 Understanding Laws of Exponents with Dividing Vocabulary: Expression Constant Coefficient Base Variable Exponent For each of the following expressions, name the constant, coefficient, base, variable, and exponent: Expression Constant Coefficient Base Variable Exponent 6x x x 3 Dividing Monomials: Expand the following, and then simplify: 1) ) 3) ) 57 x5 5) 53 x 2 y3 24 6) 7) y6 2 4

3 Understand the Laws of Exponents with Dividing Do you see a pattern when dividing same bases?? Rule: When dividing same bases, keep the base the and the exponents!!! Practice: Simplify each using the laws of exponents: 1) 510 2) x5 y x 2 y 3) ) a6 b a 4 b 5) ) x5 y 4 z 9 x 4 y 6 z 7) ) 9) a4 b c a 4 b c 9 10) x6 y 8 x 94 x5 11) 12) 4 93

4 Understand Negative and Zero Exponents Compute the value using a calculator: 1) 2 4 = 2) 5 1 = 3) 4-2 = What did you notice happens when you raise a base to a NEGATIVE exponent?? Simplify the following by using the laws of exponents (keep the base, subtract the exponents): a) b) 24 c) 5 7 Now simplify the following again by expanding out the exponents: a) b) c) Negative exponents can always be rewritten as a with a positive exponent!! *If the base is a NUMBER: take the of the base and the change exponent to a *If the base is a VARIABLE: keep the on top of the fraction and put the on the bottom with a positive exponent. Any Base raised to a zero exponent is equal to: Practice: Simplify or Rewrite the following with a positive exponent. 1) x -4 2) a -6 3) x -2 4)( 5 6 )2 5) 2x -5 6) (3x) 0 7) 3x 0 8) 12x ) ( ) 3 10) -4x -5 y 3 11) xy 0 12) 2a 0 b 2 13) x -3 y 5 z ) 4a -2 b 9 15) -5x -8 y -2 16) x 3 y -6

5 Understand Negative and Zero Exponents Simplify each if necessary and rewrite with a positive exponent: 1) 7a 0 b 3 2) ) 8x ) 10x -4 y 5 5) 8x9 2x 6) ) x3 y 7 x 2 y 7) (4x) 0 8) 4x 0 9) ( ) ) 2x 0 11) (2x) 0 12) 4x -2 y 5 z -3

6 Laws of Exponents- Dividing with Negative/Zero Exponents For each of the following expressions, name the constant, coefficient, base, variable, and exponent: Expression Constant Coefficient Base Variable Exponent 7x x x 10 Only rewrite an expression with a negative exponent when it is the FINAL ANSWER!! Simplify the following and then rewrite with a positive exponent: 8 4 1) ) ) ) 12 2 Note: If the expression has VARIABLES there is always a coefficient! You must: 1 st : 2 nd : 5x 3 5) 5x 2 12x 5 6) 6x 2 14x 11 7) 7x 2 18x 9 8) 2x 14 9x 6 9) 3x 2 10) 10x5 y 12 20xy 8 11) 4x 50 2x 25 12) 5x4 y x 14 y 8 x 12 y 7 z 4 13) x 4 y 7 z 14) z23 z ) ) 4x 6 16y 7

7 Laws of Exponents- Multiplying For each of the following expressions, name the constant, coefficient, base, variable, and exponent: Expression Constant Coefficient Base Variable Exponent 2x x 2-7 -x 4 6x 2 Multiplying Monomials: Expand the following, then simplify! 1) ) ) ) ( 2 ) ( 2 ) 5 What is the rule?? When MULTIPLYING SAME BASES, keep the base the and the exponents!! Bases as a CONSTANT: Multiply each of the following and rewrite with a positive exponent, if necessary. 5) ) ) ) ) ) 4 4 5

8 Laws of Exponents- Multiplying Bases as a VARIABLE: **Remember if there is a variable, there is ALWAYS a coefficient! MULTIPLY THE COEFFICIENT!! 11) p 5 p 7 12) 2a 4 5a 2 13) (x 5 )(y 3 ) 14) (x)(x 4 ) 15) (4b 3 )(8b -2 ) 16) (7m 4 )(m -5 ) 17) ( x ) y 4 1 x y ( ) 18) ) (3y 9 )(-4y 2 ) 20) 4x 3 2x 7 21) 5c 3 3c 9 22) 4x 2 7x 4 x

9 Laws of Exponents- Raising a Power to a Power Simplify each of the following by expanding it out and then using the laws of exponents for MULTIPLYING!! Rewrite each with a positive exponent, if necessary. 1) (5 2 ) 3 2) (7 3 ) 4 3) (2 10 ) 2 4) (9 8 ) 4 5) (3 4 ) 2 6) (9 6 ) 2 7) (6 2 ) 3 8) (6 2 ) )( 2 7 ) 2 ( 2) 1 Now let s try examples with VARIABLES: 10) ( 4x 8 ) 3 11) (3y 7 ) 4 12) 3(2a 11 ) 3 13) (5x 3 ) 3 (3y 2 ) 2 14) ( 1m 4 ) 4 15) (2x 1 ) 3 16) ( 2b 4 ) 4 17) (2x 2 ) 3 18) ( 3x 5 ) 2 (2y 2 ) 3 19) (x 4 x 2 ) 2 20) ( 2x 2 ) 3

10 Square Roots Note: We represent a square root by the symbol. List Perfect Square Roots: 1 2 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 15

11 Square Roots Problems: 1. Look at the square to the right to answer the following. 144 ft 2 a. What is the length of one side of the square? b. Maggie said that the length is -12 ft. Why would Maggie be incorrect? 2. Find all the square roots of 64. Explain your answer. 3. Find all the square roots of -64. Explain your answer. 4. A microprocessor for a phone has an area of in2. What is the side length of the microprocessor, and how many microprocessors could cover a square circuit board that has a side length of 3.5 in.? 5. A. A small square window has an area of 36. What is the length of the window? B. If a second square window has an area of 100 square inches, what is the length of each side? C. Using parts A and B complete the following. 36 = 100 =

12 Introduction to Scientific Notation Vocabulary: Scientific Notation - Example: Scientific Notation Standard Form = 259,000,000,000 Coefficient Power of 10 Rule: A number is in scientific notation if: 1) The first factor is a single digit followed by a decimal point 2) Times the second factor which is a power of x Examples: Determine if the numbers below are written in scientific notation. 1) ) ) ) Scientific Notation: Positive Exponents and Negative Exponents 5) ) ) ) 5 9

13 Introduction to Scientific Notation Scientific Notation: Real Life Situations When is it appropriate to use scientific notation in real life? Examples of Large Numbers: Examples of Small Numbers: Determine if the number in scientific notation would be written with a positive or negative exponent. 9) The weight of 10 Mack trucks 10) The width of a grain of sand Try These: Determine if the numbers below are written in scientific notation. 1) ) Determine if the numbers below are in whole numbers or decimals. 3) ) Determine if the number in scientific notation would be written with a positive or negative exponent. 5) The size of a cheek cell 6) The mass of earth Examples: 1) 3,400 x 4,500 What is the answer in standard form? What is the answer in scientific notation? 2) 4,800,000, What is the answer in standard form? What is the answer in scientific notation?

14 Introduction to Scientific Notation Try These: Write each answer in standard form (a) and scientific notation (b). 1) 678,000 x 902 2) x a) a) b) b) Classwork Determine if the numbers below are written in scientific notation. 1) ) ) ) ) ) ) ) 3 8 9) Determine if the following number in scientific notation would be written as a positive or negative exponent. 10) How many drops of water in a river 11) The weight of a skin cell 12) The width of an eyelash 13) The weight of the Brooklyn bridge Write an example of something that would be written in scientific notation with a: 14) Positive exponent 15) Negative exponent

15 Introduction to Scientific Notation Determine if the numbers below are in scientific notation or standard form. 1) ) ) ) ) 134, 987 6) ) ) ) ) 65 2 Determine if the following number in scientific notation would be written as a positive or negative exponent. 11) How many seconds in a year 12) The width of a piece of thread 13) The weight of a skyscraper 14) The weight of an electron Solve and write the following answers in standard form (a) and scientific form (b). 15) 537 x 89,000 16) 9,980,000 6,520 17) x.07 a) a) a) b) b) b) Review Work: 18) 7 3 x ) ( 1 4 ) -3 20) 4x + x 8 = 5x ) 18-3

16 Converting to and From Scientific Notation Standard Form Scientific Notation Rule: Step 1: Write the number placing the decimal point after the first non-zero digit Step 2: Write Step 3: Count the number of digits you moved the decimal point and write it as the exponent Remember: If it is a whole number the exponent is. If it is a decimal the exponent is. Examples: Convert from standard form to scientific notation. 1) 245,000,000 = 2) = 3) 500,000 = 4) = Scientific Notation Standard Form Rule: Step 1: Move decimal point the number of places indicated by the exponent. Step 2: If - Positive exponent: Move decimal point Right (Whole number- make the number larger) If - Negative exponent: Move decimal point Left (Decimal - make the number smaller) Convert from scientific notation to standard form. 5) = 6) = 7) = 8) =

17 Converting to and From Scientific Notation Making Sure a Number is Written in Scientific Notation Rule: If Decimal Point needs to move to the LEFT Exponent Increases ( ) If Decimal Point needs to move to the RIGHT Exponent Decreases (.48 3 ) * Be careful when exponent is negative. A positive, finite decimal s is said to be written in scientific notation if it is expressed as a product d 10 n, where d is a finite decimal so that 1 d < 10, and n is an integer. The integer n is called the order of magnitude of the decimal d 10 n. Write each in Scientific Notation if necessary: 9) = 10) 6 5 = 11) = 12) = 13) = 14) = Try These: Write each of the following in scientific notation: 1) 650,000 2) 23,500,000 3) ) Write each of the following in standard form: 5) ) ) ) Write each in Scientific Notation if necessary: 9) 29 6 = 10).32-7 = 11) = 12) = 13) What is the value of n in the problem: a) 91,000 = 9.1 n n = b) = 2.7 n n =

18 Converting to and From Scientific Notation Classwork: Write each of the following in scientific notation: 1) 523,000,000 2) 7,740 3) ) Write each of the following in standard form: 5) ) ) ) Write each in Scientific Notation if necessary: 9) = 10).7-3 = 11) = 12).11 5 = 13) What is the value of n in the problem: 624,000 = 6.24 n n = 14) If n = 7, find the value of 5.2 n in standard form. 15) Which number is written in the correct scientific notation form? A) 5,000 B) C) D) 50 5

19 Comparing and Ordering Scientific Notation Comparing Rule: 1) Put all values into correct scientific notation. Look at exponents first 2) If the exponents are different, the larger exponent is the bigger number 3) I f the exponents are the same, compare the coefficients of each. Examples: Which is larger? Explain in words how you knew. 1) or ) or ) or 200,000 4) or 2,500,000 5) 2 53 or ).24-2 or Compare: Use <, >, or = 7) ) ) ) million 11) Put in order from least to greatest:

20 Comparing and Ordering Scientific Notation Try These: Compare: Use <, >, or = 1) 34, ) ) ) ) Put in order least to greatest: ) The Fornax Dwarf galaxy is light-years away from Earth, while Andromeda I is light-years away from Earth. Which is closer to Earth? 7) The average lifetime of the tau lepton is seconds and the average lifetime of the neutral pion is seconds. Explain which subatomic particle has a longer average lifetime. Practice: Which is larger? 1) or ) or 2, 400 3) or ) or.0009

21 Comparing and Ordering Scientific Notation Compare: Use <, >, or = 5) ) ) ) ) ) ) ) Put in order from least to greatest: 13) ,500 14)

22 Multiplying and Dividing Scientific Notation Rules for Multiplying and Dividing Numbers in Scientific Notation without a Calculator 1 - Multiply or Divide Coefficients Using rules of multiplying or dividing decimals. 2 - Multiply or Divide powers of 10 by adding or subtracting the exponents. 3 Make sure the answer is in correct scientific notation. If you have to move the decimal to the Left, INCREASE the exponent. If you have to move the decimal to the Right, DECREASE the exponent. Examples: 1) (3.5 3 )(2 5 ) 2) (8.0 6 ) (2.5 3 ) 3) (7.2 5 )(6.5 4 ) 4) (9.9-3 ) (3 2 ) 5) A paperclip factory produces 5 2 paperclips a day. In a period of days, how many can be produced? 6) A newborn baby has about 26,000,000,000 cells. An adult has about cells. How many times as many cells does an adult have then a newborn? Write your answer in scientific notation.

23 Multiplying and Dividing Scientific Notation Try These: 1) (5 12 )(1.1 3 ) 2) ) (2.4 8 )(6-2 ) 4) ) An adult blue whale can eat krill in one day. At that rate, how many krill can an adult blue whale eat in days? 7) (6.2 4 )(3.2 3 ) 8) ( ) (6.5-4 ) 9) (1.1-5 )(1.2 2 ) 10)

24 Adding and Subtracting Scientific Notation Rules for Adding and Subtracting Numbers in Scientific Notation without a Calculator Method 1: 1 - Convert each number with the same power of 10. (* It is easier when you convert to higher exponent) 2 Add or Subtract the multipliers. 3 Write to the same power of 10. Be sure final answer is in correct scientific notation. OR Rules for Adding and Subtracting Numbers in Scientific Notation without a Calculator Method 2: 1 - Convert each number to standard form. 2 Add or Subtract. 3 Convert the answer to scientific notation. Examples: 1) ) ) ) ) (3.1 8 ) + ( ) - (1.1 8 )

25 Adding and Subtracting Scientific Notation The table below shows the debt of the three most populous states and the three least populous states. State Debt (in dollars) Population (2012) California 407,000,000, New York 337,000,000, Texas 276,000,000, North Dakota 4,000,000, Vermont 4,000,000, Wyoming 2,000,000, ) What is the sum of the debts for the three most populous states? Express your answer in scientific notation. 7) What is the sum of the population for the three least populated states? Express your answer in scientific notation. Try These: The chart below shows the distance from New York City to other cities around the world. Trip Miles NY to Orlando NY to LA NY to Rome NY to Beijing NY to Albany 1 2 1) How far is it to go from Orlando to NY to Beijing? Express your answer in scientific notation. 2) How far is it to go from LA to NY to Albany? Express your answer in scientific notation. 3) How much farther is NY to Beijing than NY to LA? Express your answer in scientific notation.

26 Adding and Subtracting Scientific Notation Classwork: 1) (7 6 ) - (5.3 6 ) 2) (3.4 4 ) + (7.1 4 ) 3) (6.3 8 ) - (8 7 ) 4) (5.6-2 ) + (2-1 ) 5) (4.3-4 ) + (5-5 ) 6) (3.7 3 ) + (2.1 4 ) 7) (8.5 4 ) + (5.3 3 ) - (1 2 ) 8) ( ) + (5.0 1 ) + ( ) 9) The distance from Neptune to the Sun is approximately km and from Mercury to the Sun is about What is the difference in their distances?

27 Applications 1. Which one doesn t belong? Explain your reasoning (3.4 6 )(4.2 3 ) (3.4)(4.2) (6 + 3) Use the table below for questions 2-4. The table below shows the debt of the three most populous states and the three least populous states. State Debt (in dollars) Population (2012) California 407,000,000, New York 337,000,000, Texas 276,000,000, North Dakota 4,000,000, Vermont 4,000,000, Wyoming 2,000,000, What is the sum of the debts for the 3 most populous states? Express your answer in scientific notation. 3. What is the sum of the debts for the 3 least populous states? Express your answer in scientific notation. 4. How much larger is the combined debt of the three most populated states than that of the three least populated states? Express your answer in scientific notation. 5. Here are the masses of the so-called inner planets of the Solar System. Mercury: kg Earth: kg Venus: kg Mars: What is the average mass of all four inner planets? Write your answer in scientific notation.

28 Applications 6. What is the difference of and written in scientific notation? 1) ) ) 2 5 4) What is the sum of 12 and expressed in scientific notation? 1) ) ) ) What is the product of,, and expressed in scientific notation? 1) 2) 3) 4) 9. What is the quotient of and? 1) 2) 3) 4) 10. What is the value of in scientific notation? 1) 2) 3) 4) 11. If the mass of a proton is gram, what is the mass of 1,000 protons? 1) g 3) g 2) g 4) g

29 Applications 12. If the number of molecules in 1 mole of a substance is, then the number of molecules in 100 moles is 1) 2) 3) 4) 13. If you could walk at a rate of 2 meters per second, it would take you seconds to walk to the moon. Is it more appropriate to report this time as or 6.02 years? 14. The areas of the world s oceans are listed in the table. Order the oceans according to their area from least to greatest. Ocean Area (ml 2 ) Atlantic Arctic Indian Pacific 6 7 Southern Mr. Murphy s yard is feet by feet. Calculate the area of Mr. Murphy s yard. 16. Every day, nearly spam s are sent worldwide! Express in scientific notation how many spam s are sent each year. 17. In 2005, text messages were sent in the United States. In 2010, the number of annual text messages had risen to 1,810,000,000,000. About how many times as great was the number of text messages in 2010 than 2005? 18. Let M = 993,456,789,098,765. Find the smallest power of 10 that will exceed M.

30 Applications 1. All planets revolve around the sun in elliptical orbits. Uranus s furthest distance from the sun is approximately x 10 9 km, and its closest distance is approximately km. Using this information, what is the average distance of Uranus from the sun? 2. A micron is a unit used to measure specimens viewed with a microscope. One micron is equivalent to inch. How is this number expressed in scientific notation? 1) ) ) ) The distance from Earth to the Sun is approximately 93 million miles. A scientist would write that number as 1) ) ) ) By the year 2050, the world population is expected to reach 10 billion people. When 10 billion is written in scientific notation, what is the exponent of the power of ten? 5. The table shows the mass in grams of one atom of each of several elements. List the elements in order from the least mass to greatest mass per atom. Element Mass per Atom Carbon Gold Hydrogen Oxygen Silver A music download Web site announced that over 4 9 songs were downloaded by 5 7 registered users. What is the average number of downloads per user?

31 Applications 7. Sara s bedroom is inches by inches. How many carpeting would it take to cover her floor? Express your answer in scientific notation. 8. The area of Alaska is times greater than the area of Rhode Island, which is meters. How many kilometers is the area of Alaska? Express your answer in scientific notation. Review Work: 9. What is the perimeter of a fenced-in yard with corresponding sides of 5x + 12 and 3x 7? 10. Three-fourths of a pan of lasagna is to be divided equally among 6 people. What part of the lasagna will each person receive? 11. The tallest mountain in the United State is Mount McKinley in Alaska. The elevation is about 2 2 x 5 3. What is the height of Mount McKinley? 12. The mass of a baseball glove is 5 x 5 x 5 x 5. Write the mass in exponential form, and then find the value of the expression.