Copyright © 2011 Pearson Education, Inc. Numbers in the Real World

Copyright © 2011 Pearson Education, Inc. Slide 3-3 Unit 3B Putting Numbers in Perspective

3-B Copyright © 2011 Pearson Education, Inc. Slide 3-4 Scientific Notation Scientific notation is a format in which a number is expressed as a number between 1 and 10 multiplied by a power of 10. Examples: 6,700,000,000 in scientific notation is 6.7  is 2.0  10  15

3-B Class Notes (1-2) Numbers in Scientific Notation Rewrite each of the following statements using scientific notation. 1. Total spending in the new federal budget is 3,500,000,000, The diameter of a hydrogen nucleus is about meter Copyright © 2011 Pearson Education, Inc. Slide 3-5

3-B Class Notes (3) Checking answers with approximations You and a friend are doing a rough calculation of how much garbage New City residents produce every day. You estimate that, on average, each of the 8 million residents produces 1.8 pounds, or.0009 ton, of garbage each day. 8,000,000 persons x.0009 ton/person 3. Your friend tells you that the answer is 225 tons. Without using your calculation, determine whether the answer is reasonable. Copyright © 2011 Pearson Education, Inc. Slide 3-6

3-B Copyright © 2011 Pearson Education, Inc. Slide 3-7 Perspective through estimation An order of magnitude estimate specifies a broad range of values. Example: Is the total annual ice cream spending in the United States measured in thousands of dollars, millions of dollars, or billions of dollars? Giving Meaning to Numbers

3-B Class Notes (4) Order of Magnitude of Ice Cream Spending Make an order of magnitude estimate of total annual spending on ice cream in the United States. Total annual spending = serving per person per year x price per serving x population Copyright © 2011 Pearson Education, Inc. Slide 3-8

3-B Copyright © 2011 Pearson Education, Inc. Slide 3-9 Perspective through comparisons Giving Meaning to Numbers

3-B Class Notes (5) US vs. World Energy Consumption Compare the US population to the world population and US energy consumption to the world energy consumption. US pop/world pop 5. What does this tell you about energy usage by Americans? Copyright © 2011 Pearson Education, Inc. Slide 3-10

3-B Class Notes (6) 6. How many average candy bars would you have to eat to supply the energy needed for 6 hours of running? Copyright © 2011 Pearson Education, Inc. Slide 3-11

3-B Copyright © 2011 Pearson Education, Inc. Slide 3-12 Giving Meaning to Numbers Perspective through scaling Verbally: “1 cm = 1 km” Graphically : As a ratio: 1 cm = 1 km means a scale ratio of 1 to 100,000

3-B Class Notes (7-8) Scale Ratio 7. A city map states “One inch represents one mile” What is the scale ratio for this map? 8. The distance from the Earth to the Sun is about 150 million kilometers. The diameter of the sun is about 1.4 million kilometers and the diameter of the Earth is about 12,760 kilometers. Put these numbers in perspective by using a scale model of the solar system with a 1 to 10 billion scale. Copyright © 2011 Pearson Educatio, Inc. Slide 3-13

3-B Class Notes (9) Distance to the Stars 9. Respond to this discussion Copyright © 2011 Pearson Education, Inc. Slide 3-14

3-B Class Notes Timeline 10. Make a simple scale drawing of this timeline using the football field analogy. Copyright © 2011 Pearson Education, Inc. Slide 3-15

3-B Class Notes (11) Case Studies How big is a university? 11. Tell why it is impossible for the President to meet all 25,000 people by taking 5 to lunch every day. Copyright © 2011 Pearson Education, Inc. Slide 3-16