Math Concept Reader
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DIGITAL FINAL PROOF
Expedition:
Antarctica
by Aenea Mickelsen
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Copyright © 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
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Printed in the United States of America
ISBN 13: 978-0-15-360204-7
ISBN 10: 0-15-360204-X
1 2 3 4 5 6 7 8 9 10 175 16 15 14 13 12 11 10 09 08 07
Math Concept Reader
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by Aenea Mickelsen
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Ms. Milburn’s students return to the classroom from lunch. Outside, it is a
hot autumn day, so the students are glad to sit down and cool off. Ms. Milburn
tells the students that she has been searching the Internet for a scientific
expedition they could follow. A scientific expedition is a planned journey, usually
to a remote area, for a scientific purpose. Sometimes scientists communicate
with students through the Internet while they are on an expedition. They
answer questions and talk about the research they are conducting.
Ms. Milburn explains that even though she could not find a current
expedition that the class could participate in, they still can plan a virtual
expedition to Antarctica. Jacob wants to know why anyone would consider
going to this cold, remote continent in the Southern Hemisphere. Ms.
Milburn asks the class if anyone can answer that question.
Someone suggests that scientists can gather interesting data about
Antarctica’s extreme weather conditions. Scientists can also study climate
issues that affect the entire world. For example, some scientists worry that
rising temperatures in Antarctica could melt much of the continent’s ice and
raise the level of the planet’s oceans.
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(
Antarctic explorers travel with sleds as the sun sets.
Ms. Milburn asks her class two questions. What information do we need
in order to plan an expedition? Would it be similar to planning a winter trip
to the local mountains?
Christopher says that it would be better to go to Antarctica in June
or July, because summer is not as cold as winter. Ms. Milburn shows the

class a map of the world and reminds the students that Antarctica is in
the Southern Hemisphere. The seasons in the Southern Hemisphere are
opposite of the seasons in the Northern Hemisphere. So while the students
may think of June and July as the hottest months of the year, they’re actually
among the coldest for Antarctica.
Since it is such a hot day, many students think that cooling off in
Antarctica sounds like a great idea. The class realizes that to plan an
expedition, they need to know more than when the seasons occur. They
need temperature information in order to make an informed decision
about when to plan their virtual expedition. They also agree that gathering
information about wind and rain will be helpful.
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)
These people pack their supplies before starting their expedition
in Antarctica.
Next, Ms. Milburn asks the class what supplies they might need for an
expedition. For instance, would the winter coats they wear where they live
keep them warm in Antarctica? Would they need special sleeping bags for
the frigid nights?
Ms. Milburn shows the class a Web site with information about
expeditions. On one journey led by explorers Ann Bancroft and Liv
Arnesen, scientists had to fit all of their supplies onto a sled that could hold
no more than 250 pounds. They packed food, cooking supplies, health
supplies, and other equipment onto the little sled. The scientists had to
choose carefully, taking the supplies they needed while staying under the
weight limit.
To get started, Ms. Milburn divides the class into three groups. The
first group will research Antarctica’s climate and temperatures. The students
in this group have to find the best month, in terms of weather, to launch

an expedition to Antarctica. The second group will research wind and rain
data. The third group will research clothing and equipment needed for
an expedition.
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*
Cuyamaca Mountains Average Daily Temperature
Month
10
15
20
25
5
0
Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec.
Temperature (in Degrees Celsius)
Ms. Milburn begins by sharing some local weather data with the class.
She shows the students a graph that displays temperature data for the nearby
mountain range. Looking at the local data will give the class something
familiar to which they can compare the Antarctica data.
Ms. Milburn tells the students that the lowest temperature ever recorded
in the local mountains is ¯22 degrees Celsius. That temperature was
recorded in February 1998. Together, she and the students look at the data
to see what else they can learn.
As expected, the class determines that the winter months of December,
January, and February are the coldest months in their local mountain range.
The average temperature in January is about 4 degrees Celsius. The average
temperature in July, meanwhile, is the warmest at about 21 degrees Celsius.
Compared to January, July is about 17 degrees warmer. In March, the
average temperature is about 7 degrees Celsius, which is 3 degrees warmer

than January.
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The first group of students looks for temperatures in Antarctica. They
focus on two different locations, McMurdo Base and Mawson Station.
McMurdo Base, run by the United States, is the starting point for many
expeditions in Antarctica. Scientists study geology, marine biology,
meteorology, and more. Mawson Station is run by Australia. Some of the
scientists at Mawson Station are researching how the climate of Antarctica
affects the rest of the world.
As the group searches for temperature data, they find some amazing
information. There is a Russian station called Vostok (vahss-TOKE). This
station is very close to the South Pole and holds the record for the coldest
recorded temperature on Earth at about ¯89 degrees Celsius. Scientists
recorded the temperature on July 21, 1983.
The students use an equation to calculate that the record temperature at
Vostok is 67 degrees colder than the lowest temperature recorded in their
local mountains.
¯22 – ¯89 = ¯22 + 89 = |¯89| – |22| = 89 – 22 = 67
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,
Average Temperature (in Degrees Celsius)
McMurdo Base Average Daily Temperature
Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec.
High 0 ¯6 ¯14 ¯17 ¯18 ¯18 ¯21 ¯22 ¯20 ¯15 ¯6 ¯1
Low ¯5 ¯11 ¯20 ¯24 ¯26 ¯26 ¯30 ¯31 ¯28 ¯22 ¯12 ¯6

Mawson Station Average Daily Temperature
Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec.
High 3 ¯1 ¯7 ¯12 ¯14 ¯14 ¯15 ¯16 ¯15 ¯10 ¯3 2
Low ¯3 ¯7 ¯13 ¯17 ¯19 ¯20 ¯21 ¯22 ¯21 ¯16 ¯9 ¯3
The students examine the average high temperatures in the two
locations over a period of twelve months. At McMurdo Base, the highest
temperature occurs in January and is 0 degrees Celsius. At Mawson Station,
temperatures average about 3 degrees Celsius in January. That makes it 3
degrees warmer than McMurdo.
Next the students wonder which month is usually the coldest. They
quickly determine that August is the coldest month at both locations.
The average high temperature at McMurdo Base in August is ¯22 degrees
Celsius. At Mawson Station, the average high temperature is about ¯16
degrees Celsius. Mawson is about 6 degrees Celsius warmer in August.
At McMurdo Base, the average low temperature in August is ¯31
degrees Celsius. That is about 9 degrees warmer than the average low
temperature at Mawson Station.
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-
Atlantic Ocean
Pacific Ocean
McMurdo Base
Indian Ocean
Southern Ocean
Ross
Ice Shelf
A N TA R C T I C A
Mawson Station
Davis

Neumayer
Vostok
WILKES LAND
South Pole
Ronne
Ice Shelf
This map shows the continent of Antarctica.
The second group of students looks for information about the wind
at McMurdo Base and Mawson Station. They find that researchers often
record the wind speed at these two locations. The group looks at those
averages for each month of the year.
At McMurdo, the highest average wind speed in March is about
27 km/h (kilometers per hour). At Mawson Station, March wind speeds
are about 38 km/h. The difference in wind speeds in March is about
11 km/h. June has the highest average wind speed at about 43 km/hr. At
McMurdo Base, the average wind speed in June is 25 km/h.
43 – 25 = 18
The difference in wind speeds in June is about 18 km/h.
Next the group finds the two locations on a map of Antarctica. They
learn that Mawson Station is located on the coast of the Indian Ocean,
while McMurdo Base is on the Pacific Ocean. They wonder if the different
locations might affect the wind speeds.
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.
This is the Ross Ice Shelf, near McMurdo Base.
Now, the group looks for information on the average rainfall each
location receives per month. They analyze the data and discover that
McMurdo Base gets very little rainfall. February has the highest average
with 25 mm of rain, while September and November have the lowest

average with 10 mm of rain.
When the students look at the data for Mawson Station, they
discover that over the course of a year Mawson gets only about 50 mm of
precipitation. Why is there so little precipitation? It is so cold that when
it rains, the rain falls as snow instead. The average precipitation across
Antarctica is about 50 mm. That is a very small amount of precipitation. If it
weren’t for all the ice, Antarctica would be the world’s largest desert. In fact,
Antarctica is classified as a cold desert.
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&%
Metric Wind Chill Chart
Temperature (in Degrees Celsius)
10 5 0 ¯5 ¯10 ¯15 ¯20 ¯25 ¯30 ¯35 ¯40 ¯45 ¯50
10
8.6 2.7 ¯3.3 ¯9.3 ¯15.3 ¯21.1 ¯27.2 ¯33.2 ¯39.2 ¯45.1 ¯51.1 ¯57.1 ¯63.0
15
7.9 1.7 ¯4.4 ¯10.6 ¯16.7 ¯22.9 ¯29.1 ¯35.2 ¯41.4 ¯47.6 ¯53.7 ¯59.9 ¯66.1
20
7.4 1.1 ¯5.2 ¯11.6 ¯17.9 ¯24.2 ¯30.5 ¯36.8 ¯43.1 ¯49.4 ¯55.7 ¯62.0 ¯68.3
25
6.9 0.5 ¯5.9 ¯12.3 ¯18.8 ¯25.2 ¯31.6 ¯38.0 ¯44.5 ¯50.9 ¯57.3 ¯63.7 ¯70.2
30
6.6 0.1 ¯6.5 ¯13.0 ¯19.5 ¯26.0 ¯32.6 ¯39.1 ¯45.6 ¯52.1 ¯58.7 ¯65.2 ¯71.7
35
6.3 ¯0.4 ¯7.0 ¯13.6 ¯20.2 ¯26.8 ¯33.4 ¯40.0 ¯46.6 ¯53.2 ¯59.8 ¯66.4 ¯73.1
40
6.0 ¯0.7 ¯7.4 ¯14.1 ¯20.8 ¯27.4 ¯34.1 ¯40.8 ¯47.5 ¯54.2 ¯60.9 ¯67.6 ¯74.2
45
5.7 ¯1.0 ¯7.8 ¯14.5 ¯21.3 ¯28.0 ¯34.8 ¯41.5 ¯48.3 ¯55.1 ¯61.8 ¯68.6 ¯75.3

50
5.5 ¯1.3 ¯8.1 ¯15.0 ¯21.8 ¯28.6 ¯35.4 ¯42.2 ¯49.0 ¯55.8 ¯62.7 ¯69.5 ¯76.3
55
5.3 ¯1.6 ¯8.5 ¯15.3 ¯22.2 ¯29.1 ¯36.0 ¯42.8 ¯49.7 ¯56.6 ¯63.4 ¯70.3 ¯77.2
60
5.1 ¯1.8 ¯8.8 ¯15.7 ¯22.6 ¯29.5 ¯36.5 ¯43.4 ¯50.3 ¯57.2 ¯64.2 ¯71.1 ¯78.0
Wind Speed (km/h)
The third group of students looks for information on clothing they
could wear while in Antarctica. Wind is an issue. The students already
know that the combination of wind speed and temperature is called wind
chill. Sometimes the wind chill can make the temperature outside feel
colder than the reading on a thermometer. The students decide to look
for temperature ratings for jackets. Temperature ratings will tell them just
how cold it can be outside before they’ll feel it when they’re wearing a
jacket. Not all of the jackets that look suitable for expeditions come with
temperature ratings.
The students gather the information on temperature ratings for jackets.
They find that one jacket is rated to ¯23 degrees Celsius, a second one to
¯26 degrees Celsius, and the third to ¯29 degrees Celsius. By comparison,
the temperature rating of a lined trench coat is rated to ¯12 degrees Celsius.
The students calculate that to go from the ¯29-rated jacket to the trench
coat, the temperature would have to rise about 17 degrees Celsius.
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&&
Sleeping Bag Temperature
Ratings and Weights
Temperature Rating
(in Degrees Celsius)
Weight (in Pounds

and Ounces)
¯40 5 pounds
¯29 4 pounds 4 ounces
¯18 3 pounds 11 ounces
¯7 2 pounds 4 ounces
Now the group looks for some of the equipment that will be needed
for the expedition. The students find pictures of tents in Antarctica, as well
as photographs of buildings. The group assumes that because it’s so cold in
Antarctica, the scientists do not sleep outside all of the time. They think
it must be hard to keep buildings warm on the inside in such an extreme
climate, so a comfortable and warm sleeping bag sounds like a vital piece of
equipment.
The group makes a chart to compare the data on sleeping bags. One
sleeping bag is rated to ¯40 degrees Celsius. That particular bag is also the
heaviest. The group notices that the lower the temperature rating, the
heavier the bag. The sleeping bag with the lowest temperature rating can
keep one warmer by at least 11 degrees over the one rated at ¯29 degrees
Celsius.
As the group looks at sleeping bags, they discover an interesting fact:
¯40 degrees Celsius is the same temperature as ¯40 degrees Fahrenheit! It is
the only temperature at which the two scales give the same number. The
students know that whichever scale they use, ¯40 is very cold!
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At the end of the week, the students review the data they collected. Ms.
Milburn asks the groups to present their findings before the class.

The first group reports their findings on the temperatures in Antarctica.
They recommend planning an expedition for January, because the average
temperature in Antarctica that time of year is around ¯2 degrees Celsius.
That is 24 degrees warmer than in August, when the average temperature is
about ¯26 degrees Celsius.
The second group presents the information on wind speed at McMurdo
Base and Mawson Station. At first, the students looked at data for the
months of March and June, but they later added data for January to their
investigation. Group 2 explains that the average wind speed at Mawson
Station in January is about 27 km/h. That is about 16 km/h less than
the average wind speed in June. They also report that rain is not an issue
in Antarctica. They agree that January would be a good month for an
expedition.
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&(
Jackets and other gear are important for people who work in the
extreme Antarctic temperatures.
The third group tells the class what they discovered when they
researched various jackets and sleeping bags. They conclude that based
on what the first group reported about temperatures, a jacket with a
temperature rating of ¯23 degrees Celsius would work well for the
conditions in Antarctica. It turns out that the warmest sleeping bag
they found might be too warm if a person slept inside a building.
Since the temperature is ¯2 degrees Celsius outside, a sleeping bag rated
to ¯7 degrees Celsius would be about right for someone sleeping inside
a building.
Finally, Ms. Milburn says that she would be interested in one more
set of data. She asks if any of the groups found information about hours of
daylight in Antarctica. Ms. Milburn invites the whole class to join her at

a computer station as they search for that information.
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&)
The class researched the number of hours of sunshine in Antarctica
during the year.
The class finds sunlight data for Mawson Station. There are days
in December and January when it is light for 24 hours at a time. Next
the class looks for Antarctica’s winter hours of sunshine. They find
the average for June, when the sky is dark most of the day, with some
twilight. Twilight is the time of day between daylight and darkness. In
June, Mawson Station gets no daylight, or daily sunshine. So the average
daily sunshine in June is 24 hours less than January, or zero.
The class has a hard time imagining a day with zero hours of
daylight. Antarctica is so far away from the equator that daily sunshine is
an issue. That information gives them another reason to pick January as
an ideal month for an expedition.
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&*
The class is ready to take a virtual expedition into Antarctica.
Ms. Milburn congratulates the groups for gathering relevant
information. Now the class will organize the data they found. She stands
before the class and writes, “Antarctica: A Place of Extremes” on the board.
She invites the students to share their favorite facts about Antarctica.
One student tells Ms. Milburn that the record low temperature on Earth
was about ¯89 degrees Celsius at Vostok on July 21, 1983. Another says that
winds reach 322 km/hr on Commonwealth Bay, in the southern part of the
continent. Someone adds that ice shelves are all along the coast. The largest
of these is the Ross Ice Shelf, which is two times the size of the island of

New Zealand. Another student shares that the thickest ice on Earth is found
in Wilkes Land, where the ice reaches a depth of 4,776 meters.
Finally, Ms. Milburn tells the class that she found an extreme fact while
reading about Mawson Station. There, researchers are limited to a single
three-minute shower each day. Since the water for bathing comes from
melting ice, it takes a lot of energy to produce it.
With all the facts the class has gathered, they are now well prepared to
undertake their virtual expedition into Antarctica.
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&+
Glossary
Celsius a metric scale for measuring temperature in
which the freezing point of water is 0° and the boiling
point of water is 100°
Commonwealth Bay a bay at the entrance between
Point Alden and Cape Gray in Antarctica
kilometer a metric unit for measuring distance,
abbreviated km. 1 km = 1,000 m.
Mawson Station an Australian base in Antarctica,
named after the explorer Douglas Mawson
McMurdo Base the largest scientific station in Antarctica
meteorology the study of the atmosphere, including
weather and climate
precipitation water that falls as rain or snow
Vostok a Russian research station in Antarctica, built
in 1957
wind chill the apparent temperature when the wind
blows in cold weather
Photo Credits: cover: Bancroft Arnesen Explore/yourexpedition.com; p. 2:

Jupiter Images Corporation; p. 4: Bancroft Arnesen Explore/yourexpedition.com;
p. 6: Jupiter Images Corporation; p. 9: NOAA; p. 11: Bancroft Arnesen Explore/
yourexpedition.com; p. 12: Jupiter Images Corporation; p. 13: NOAA;
p. 14: NOAA; p. 15: NOAA
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Think and Respond
1. The highest temperature in August at Macquarie
Island, Antarctica, is about 9 degrees Celsius. The
lowest temperature is
–
9 degrees Celsius. What is the
difference in temperatures?
2. The warmest temperature recorded recently at Davis
in Antarctica is
–
42 degrees Celsius. The coldest
temperature recently recorded is
–
55 degrees Celsius.
What is the difference in temperatures?
3. If the current temperature is
–
17 degrees Celsius, how
many degrees would the temperature need to rise to
match yesterday’s high temperature of
–
14 degrees
Celsius?
4. Look at the table on page 11. Use the table to write a

problem. Write an equation to solve the problem.
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