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Math Concept Reader
Math Concept Reader Listening to the World of Science us61xs_lay_0700606f_sb.indd 6/6/07 10:55:40 AM DIGITAL FINAL PROOF ca66xs_lay_070109af_kb.indd 1/9/07 10:12:46 PM Math Concept Reader Listening to the World of Science by Carri Stuhr Copyright © by Gareth Stevens, Inc All rights reserved Developed for Harcourt, Inc., by Gareth Stevens, Inc This edition published by Harcourt, Inc., by agreement with Gareth Stevens, Inc No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the copyright holder Requests for permission to make copies of any part of the work should be addressed to Permissions Department, Gareth Stevens, Inc., Reader’s Digest Road, Pleasantville, NY 10570 HARCOURT and the Harcourt Logo are trademarks of Harcourt, Inc., registered in the United States of America and/or other jurisdictions Printed in the United States of America ISBN 13: 978-0-15-360492-8 ISBN 10: 0-15-360492-1 If you have received these materials as examination copies free of charge, Harcourt School Publishers retains title to the materials and they may not be resold Resale of examination copies is strictly prohibited and is illegal Possession of this publication in print format does not entitle users to convert this publication, or any portion of it, into electronic format 10 175 16 15 14 13 12 11 10 09 08 07 us61xs_lay_0700606f_sb.indd 6/6/07 10:36:13 AM Chapter 1: Sound Science Kaja grabs her coat and backpack from her locker and hurries down the hall to the school’s media center She is going to the Science Club meeting The Science Club meets once a week Ms Wilson, the group’s leader, is a science teacher at the school who helps students in the club explore science through different activities When Kaja arrives, she sees other club members standing around a computer looking at digital photographs of some of the activities the Science Club members participated in last year There is a picture of Mariana looking through a microscope Another photo shows Kim and Julia standing next to a pond with jars in their hands There is also a photo of Henry working on a Science Fair project Kaja sees a picture of herself standing in front of a science museum us61xs_lay_0700606f_sb.indd 6/6/07 10:36:14 AM A Science Club member enjoys a night of stargazing Ms Wilson asks the students to look at the photographs and talk about their favorite activities from last year Kaja says she liked learning about the solar system on the club’s trip to a science museum Mariana thought it was interesting to study how wind can generate electricity Jayden says that he learned how to identify several constellations after he spent a night stargazing with the Science Club As the students talk, Ms Wilson writes these topics on the board “The Science Club participates in many activities,” says Ms Wilson “We also get to learn a lot of amazing things about science The beginning of the year is a great time to share our experiences with other students I want us to work on a project that will encourage more students to participate in the Science Club.” us61xs_lay_0700606f_sb.indd 6/6/07 10:36:17 AM Ms Wilson thinks it would be fun for the Science Club to create podcasts about their favorite science topics A podcast is an audio or video recording The students will create audio podcasts and post them on the club’s Web page Students at school, and even the public, can go to the Web page and download the podcasts to an audio player or a computer Then they can listen to the reports on different science topics The group starts to talk about their experiences with podcasting Jayden says he listens to podcasts on the computers in the media center Kaja says she knows of a Web page where students share podcasts Most of the students have listened to podcasts This is their first time making one, though! Everyone wants to try making a podcast They can share what they have learned about science with other students in the school Podcasts can be downloaded onto an audio player us61xs_lay_0700606f_sb.indd 6/6/07 10:36:18 AM Ms Wilson discusses writing podcasts with her class Ms Wilson says the first step is to select a topic they want to share with other students She points to the ideas the students listed as their favorite activities She encourages the group to choose topics that other students may want to hear more about Once the students have selected a topic, they can research, write and record the podcasts Ms Wilson suggests that students make their podcasts about ten minutes long The first part of the podcast should be an introduction The next part of the podcast should cover two or three main points They should finish the podcast with a summary of what has been talked about already Ms Wilson gives the group advice on writing a podcast “It is important to keep the listener in mind,” she says “Help the listener understand the science through the words you choose, and make your writing style fun and engaging The listener will stay interested if you share information and give examples.” us61xs_lay_0700606f_sb.indd 6/6/07 10:36:20 AM Chapter 2: Writing a Podcast The students break into groups to write their podcasts Julia and Jayden talk about the night the Science Club went stargazing They used a telescope to see the stars and several planets They also learned the names and positions of several constellations They think other students would be interested in a podcast about the night sky and its stars The podcast will describe how scientists measure the brightness of stars Then it will describe how to find constellations in the night sky Julia opens her science book to look for more information on the brightness of stars She finds a chart that shows the apparent magnitude of stars on a scale from one to six Apparent magnitude measures how bright a star appears to the human eye on Earth The scale was created by Hipparchus, an ancient Greek astronomer who used the scale to describe the brightness of the stars A star with a smaller magnitude is actually easier to see than one with a larger magnitude A star with a magnitude of is much brighter than a star with a magnitude of Apparent Magnitude Scale G G us61xs_lay_0700606f_sb.indd G G G G 6/6/07 10:36:21 AM Jayden thinks they should tell listeners the apparent magnitude of stars that are easy to find He looks through a book and finds a chart with the names of stars and their apparent magnitudes Julia points to the apparent magnitude of Polaris, the North Star Its apparent magnitude is 2.02 She also finds the apparent magnitude of Vega, a star that shines brightly in the summer sky Vega has an apparent magnitude of 0.03 Julia subtracts the apparent magnitude of Vega from the apparent magnitude of Polaris 10 12 2.02 – 0.03 1.99 The difference in apparent magnitude between the two stars is 1.99 Based on the subtraction, Julia estimates there are about two units of apparent magnitude between the two stars Julia reads that as you move down one unit on the apparent magnitude scale, a star becomes 2.5 times brighter To find out how much brighter Vega is than Polaris, she multiplies 2.5 by 2.5 to find the product 2.5 × 2.5 = 6.25 Jayden says, “Based on our calculation, we can say that Vega appears to be about six times as bright as Polaris We can post the apparent magnitude scale on the club’s Web page, and then we can tell listeners where to find the scale.” Stars and their Apparent Magnitude Name Apparent Magnitude Betelgeuse 0.50 Castor 1.57 Altair 0.77 Deneb 1.25 Polaris 2.02 Pollux 1.14 Riegel 0.12 Vega 0.03 us61xs_lay_0700606f_sb.indd 6/6/07 10:36:22 AM Wind turbines capture energy from the wind Mariana and Kim want to write a podcast about wind energy Last year, the Science Club visited a wind farm where wind turbines are used to harvest the power of wind energy A turbine is a type of modern windmill that looks like a giant tower with large blades on the top A turbine turns the energy from the wind into electricity “We can start the podcast with some basic facts about wind energy as an alternative energy source,” Mariana says “Then we can talk about how much energy a turbine makes.” At the wind farm, the girls learned that the wind has been a source of energy for many years Farmers once used the energy from windmills to grind grain and pump water from the ground In the 1930s, windmills generated electricity The wind turbines built today operate on the same principle as windmills Wind turns the giant blades of the turbine The turning blades operate a generator that produces electricity Power companies use power lines to collect the electricity produced by wind farms Wind turbines in the United States produce enough energy to power 1.6 million homes us61xs_lay_0700606f_sb.indd 6/6/07 10:36:24 AM Kim and Mariana collected data from three wind turbines on the farm when they visited it last year They find the data and look at their notes The data show how many kilowatt hours (kWh) of energy the wind turbines produced in one month A kilowatt hour is a measure of how much energy is used or produced Wind turbines generate a great deal of energy! These three turbines generate a total of more than 600,000 kilowatt hours of energy each month Kilowatt Hours of Energy Produced by Three Wind Turbines in One Month Turbine Energy Produced (in kWh) Turbine A 271,604 Turbine B 189,307 Turbine C 170,525 Total for Turbines A, B, and C 631,436 Mariana thinks an example would be helpful because it will make the data easier to understand She thinks they should say how many homes 600,000 kilowatt hours of energy will power for one month Kim looks at data about home energy use on the Internet Suppose that an average home uses about 900 kilowatt hours each month Kim and Mariana write an equation to help them estimate how many homes could be powered by the three turbines 630,000 ÷ 900 = 700 “We can say that three turbines provide enough energy each month for about 700 homes,” Mariana says Kim and Mariana discover that three wind turbines can provide electricity for many homes us61xs_lay_0700606f_sb.indd 6/6/07 10:36:26 AM Neptune Earth Kaja and Henry will write a podcast about the distances between the planets and other objects in the solar system Kaja and Henry agree that their favorite activity last year was the trip to a science museum They saw a movie on the solar system at the museum’s planetarium A planetarium is a domed theater which displays the position of stars and planets on a large screen Kaja wants to write a podcast that takes students on an audio journey through the solar system Kaja and Henry could describe the distance between the sun and the planets This might help students realize the large difference in distances between objects in the solar system Henry sits down at the computer to search for information He finds a table It lists the distances between the sun and the planets He picks two distances as examples The table shows that the distance from the sun to Earth is 150,000,000 kilometers Neptune is about 4,498,000,000 kilometers from the sun Kaja says it would be easier to use scientific notation to compare these distances She opens a notebook and writes both numbers in standard form and in scientific notation 150,000,000 = 1.5 × 108 4,498,000,000 = 4.498 × 109 10 us61xs_lay_0700606f_sb.indd 10 6/6/07 10:36:27 AM Henry agrees that scientific notation is helpful for writing large numbers He thinks there may be another way to help listeners understand the distances between the planets Henry remembers the Science Club made a model of the solar system It helped them understand the distance between the planets on a much smaller scale To create a scale, they divided each distance by the same number It might be easier to describe the distances in the podcast if they used a smaller scale He uses the scale of 1,000,000 km equals m Kaja and Henry divide the distance from the sun to Earth by 1,000,000 Then they divide the distance from the sun to Neptune by 1,000,000 This tells them the scale distance in meters 150,000,000 ÷ 1,000,000 = 150 4,498,000,000 ÷ 1,000,000 = 4,498 Using this scale, Earth would be about 150 meters from the sun Neptune would be about 4,498 meters from the sun! Kaja and Henry will use the same scale to find the distance between the sun and the other planets These measurements will help listeners compare the distances Approximate Distance From the Sun to the Planets Planet Distance from the sun (in kilometers) Mercury 58,000,000 Venus 108,000,000 Earth 150,000,000 Mars 228,000,000 Jupiter 778,000,000 Saturn 1,427,000,000 Uranus 2,871,000,000 Neptune 4,498,000,000 11 us61xs_lay_0700606f_sb.indd 11 6/6/07 10:36:28 AM Chapter 3: Ready, Set Record At the next Science Club meeting, students finish writing their podcasts Each group gives its script to a review group The review group offers suggestions for changes “How did you choose the scale for the planets?” Jayden asks Kaja and Henry “You might want to include your scale on the club’s Web page.” “I liked your podcast on stargazing,” Kaja says to Julia and Jayden “I thought you could add a sentence about which planets you can see in the night sky I know that Venus is a planet that you can find in the sky on a clear night.” Ms Wilson asks each group to read its script aloud This will help them find the length of their podcast When they finish reading, other members of the Science Club can comment on the podcast “As you listen to the podcast, ask yourself if there is anything you did not understand,” Ms Wilson suggests “Think about whether or not you would like something explained in more detail.” 12 us61xs_lay_0700606f_sb.indd 12 6/6/07 10:36:28 AM Kim reads her part of the podcast on wind energy Kim and Mariana volunteer to read their podcast They start their podcast with an introduction Then they describe their visit to the wind farm They explain how much energy the three wind turbines make Finally, the girls say how much energy a family uses each month Kim and Mariana ask for input from the other students Jayden thinks they did a great job of describing the wind farm Kaja liked the podcast She says it helped her understand just how much energy turbines can make Ms Wilson found it interesting to hear how much energy a family uses in one month She has a suggestion The students could talk about how much energy an appliance uses in one day She gives the example of a fan that uses 100 watts of electricity It is used for three hours each day Ms Wilson multiplies 100 by to find the total number of watts “A 100 watt fan that operates for three hours uses 300 watts of electricity a day,” says Ms Wilson “You could compare this amount to the electricity used by a larger appliance, such as a refrigerator or a stove.” 13 us61xs_lay_0700606f_sb.indd 13 6/6/07 10:36:32 AM Jayden and Julia use a computer and software to record their podcast The students are ready to record their podcasts Julia and Jayden open a program on the computer It will help them make their podcast Julia clicks the record button She starts to read the first part of their podcast She clicks the stop button She looks at a counter on the screen that shows that her part took 210 seconds Julia divides 210 by 60 seconds in one minute to find the length of her part in minutes 210 ÷ 60 = 3.5 Julia’s part of the podcast is 3.5 minutes long Jayden clicks the record button and the counter continues to add seconds When Jayden finishes, they have recorded for a total of 570 seconds Julia subtracts to find the length of Jayden’s part 570 – 210 = 360 Jayden’s part of the podcast lasts 360 seconds Julia and Jayden want to find how many minutes are equal to 360 seconds Julia divides the number of seconds by 60 seconds 360 ÷ 60 = The total length of Jayden’s part is six minutes The next step is to find the total length of their podcast + 3.5 = 9.5 Their podcast is 9.5 minutes long 14 us61xs_lay_0700606f_sb.indd 14 6/6/07 10:36:34 AM After all of the podcasts are recorded, Ms Wilson suggests adding sound effects and music She says these types of special effects can help students enjoy the podcast Mariana wants to add the sound of blowing wind to her podcast Henry and Kaja think their podcast would be livelier with a little music in the background Ms Wilson reminds students they need permission to use sound effects and music She says the computer program they use has many songs and sound effects They can use them without requesting special permission because the permission is included as part of the program Once the groups finish adding music and sound effects to their podcasts, Ms Wilson uploads them to the Science Club’s Web page She adds some digital photos and charts to the page, too The images will help other students understand the topics described in the podcasts The Web page looks great! Students and other listeners can easily download the podcast audio files They can learn more about the Science Club and their activities Everyone hopes the podcasts will bring more students to the next Science Club meeting Students download the podcast audio files from the Science Club’s Web page and listen to the reports 15 us61xs_lay_0700606f_sb.indd 15 6/6/07 10:36:36 AM Glossary alternative energy source a renewable source of power such as wind, water, or the sun apparent magnitude the brightness of the stars as seen from Earth constellation a group of stars that has been named Some examples include Ursa Minor, Orion, and Libra galaxy a large group of stars generator a machine that makes energy kilowatt a unit of measure for power kilowatt = 1,000 watts planetarium a domed building that houses a screen where images of the solar system are viewed podcast an audio recording that can be downloaded from the Internet A podcast may also include pictures and video turbine a machine that has blades or paddles which are rotated by steam, air, gas, or water watt a unit of measure for power 1,000 watts = kilowatt wind farm an area of land that has wind turbines that are used to generate energy Photo credits: cover © Michael Newman/PhotoEdit, Inc; p © Tony Freeman/PhotoEdit, Inc.; p Photodisc Green/Getty Images; p David Young-Wolff/Stone/Getty Images; p Photo courtesy of the U.S Department of Energy; p Kevin Cooley/Stone+/Getty Images; p 10 © iStockphoto/George Argyropoulos; p 13 © Jonathan Nourok/PhotoEdit, Inc.; p 14 Michael Goldman/The Image Bank/Getty Images; p 15 © David Young-Wolff/PhotoEdit, Inc 16 us61xs_lay_0700606f_sb.indd 16 6/6/07 10:36:37 AM Think and Respond Look at the chart on page 11 Use the distances in standard notation from the sun to Mercury and from the sun to Uranus, and write these distances in scientific notation Suppose Kaja and Henry produce another podcast that runs 750 seconds long How would they find the number of minutes their podcast lasts? How long, in minutes, is their podcast? Kim and Mariana found the monthly output of energy in kilowatt hours for thr ee turbines They wrote the amounts in this table Turbine Energy Produced (in kWh) Turbine A 183,230 Turbine B 228,625 Turbine C 193,349 How much total energy, in kilowatt hours, did these three turbines produce? The chart on page 11 shows the distances between the sun and the planets using standard notation Describe how you would find the distance between two planets listed in the table Then choose two of the planets and find the distance between them us61xs_lay_0700606f_sb.indd 17 6/6/07 11:10:00 AM ... the public, can go to the Web page and download the podcasts to an audio player or a computer Then they can listen to the reports on different science topics The group starts to talk about their... says the first step is to select a topic they want to share with other students She points to the ideas the students listed as their favorite activities She encourages the group to choose topics... uses the scale of 1,000,000 km equals m Kaja and Henry divide the distance from the sun to Earth by 1,000,000 Then they divide the distance from the sun to Neptune by 1,000,000 This tells them the