Math Concept Reader MCR g6 listening to the world of science

Listening to the
World of Science
Math Concept Reader
us61xs_lay_0700606f_sb.indd 1 6/6/07 10:55:40 AM
Walk the Distance
by Jennifer Marrewa
ca66xs_lay_070109af_kb.indd 4 1/9/07 10:12:46 PM
DIGITAL FINAL PROOF
by Carri Stuhr
Listening to the
World of Science
Math Concept Reader
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ISBN 13: 978-0-15-360492-8
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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 acti
vities the Science Club members participated in
last year. There is a picture of Mariana looking through a

micr
oscope. 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

pictur
e of herself standing in front of a science museum.
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
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 ho
w 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. W
ilson. “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
.”
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
Podcasts can be downloaded onto
an audio player.

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

do
wnload 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.
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
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.”
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Chapter 2:
Writing
a Podcast
6
5
4
3
2
1
G
G
G
G
G
G
Apparent Magnitude Scale

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 star
s 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 1 is much brighter than a
star with a magnitude of 6.
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
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
Stars and their Apparent Magnitude
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

appar
ent magnitude of 0.03. Julia subtracts the apparent magnitude
of V
ega from the apparent magnitude of Polaris.
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

appear
s to be about six times as bright as Polaris. We can post the
appar
ent magnitude scale on the club’s Web page, and then we can

tell listeners where to find the scale.”
1210
1
9
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
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 ar
e used to harvest the power of wind energy. A turbine
is a type of moder
n 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 ho
w 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 electr
icity.
The wind turbines built today operate on the same principle

as windmills. W
ind turns the giant blades of the turbine. The
tur
ning 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.

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
Kim and Mariana
discover that
three wind
turbines can
provide electricity
for many homes.
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
Kilowatt Hours of Energy Produced by Three Wind Turbines in One Month
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.
Mariana thinks an example would be helpful because it will make the

data easier to under
stand. She thinks they should say how many homes
600,000 kilo
watt 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

b
y the three turbines.
630,000 ÷ 900 = 700
“We can say that three turbines provide enough energy each month for
about 700 homes,” Mariana says.
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10
Kaja and Henry will write a podcast about the distances between the planets
and other objects in the solar system.
Neptune
Earth
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

betw
een 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 × 10
8
4,498,000,000 = 4.498 × 10
9
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11
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
Approximate Distance From the Sun to the Planets
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

descr
ibe the distances in the podcast if they used a smaller
scale. He uses the scale of 1,000,000 km equals 1 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 meter
s.
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.
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Chapter 3:
Ready, Set. . .
Record
1
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

an
ything you did not understand,” Ms. Wilson suggests. “Think
about whether or not you would like something explained in
more detail.”
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1
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 3 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.”
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1
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. J
ulia divides the number of seconds by 60 seconds
360 ÷ 60 = 6
The total length of Jayden’s part is six minutes.
The next step is to find the total length of their podcast.
6 + 3.5 = 9.5
Their podcast is 9.5 minutes long.
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1
Students download the podcast audio files from the Science Club’s Web page and
listen to the reports.
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 enjo
y the podcast. Mariana wants to add the sound of
b
lowing 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

per
mission is included as part of the program.
Once the groups finish adding music and sound effects to their

podcasts, Ms. W
ilson 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 acti
vities. Everyone hopes the podcasts will
bring more students to the next Science Club meeting.
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1
Photo credits: cover © Michael Newman/PhotoEdit, Inc; p. 3 © Tony Freeman/PhotoEdit,
Inc.; p. 4 Photodisc Green/Getty Images; p. 5 David Young-Wolff/Stone/Getty Images; p. 8
Photo courtesy of the U.S. Department of Energy; p. 9 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.
Glossary
Think and Respond
alternative energy source a renewable source of power such as
wind, water, or the sun
apparent magnitude the br
ightness of the stars as seen from Earth
constellation a g

roup of stars that has been named. Some examples
include Ursa Minor, Orion, and Libra.
galaxy
a large group of stars
generator a machine that mak
es energy
kilowatt a unit of measur
e for power. 1 kilowatt = 1,000 watts
planetarium a domed b
uilding that houses a screen where images
of the solar system are viewed
podcast an audio r
ecording that can be downloaded from the
Internet. A podcast may also include pictures and video.
turbine a machine that has b
lades or paddles which are rotated by
steam, air, gas, or water
watt a unit of measur
e for power. 1,000 watts = 1 kilowatt
wind farm an ar
ea of land that has wind turbines that are used to
generate energy
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Think and Respond
1. 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.
2. 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?
3. Kim and Mariana found the monthly output of energy in
kilowatt hours for thr ee turbines. They wrote the amounts in
this table.
How much total energy, in kilowatt hours, did these three
turbines produce?
4. 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.
Turbine Energy Produced (in kWh)
Turbine A 183,230
Turbine B 228,625
Turbine C 193,349
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