Vocabulary
Name
exquisite
intrinsic
meticulously
excavation
bedrock
intriguing
methodical
embark
Use each pair of vocabulary words in a single sentence.
1. excavation, intriguing
2. meticulously, bedrock
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3. methodical, intrinsic
4. exquisite, embark
Practice • Grade 6 • Unit 6 • Week 4
281
Comprehension: Sequence Graphic Organizer
Name
Read the selection. Complete the sequence graphic organizer.
Event
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Practice • Grade 6 • Unit 6 • Week 4
Comprehension and Fluency
Name
Read the passage. Use the summarize strategy to restate the
most important points.
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Ancient Threads Reveal Early Weavers
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27
42
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From deep in a mountain cave in Peru, South America, ancient bits of
cloth have given scientists a peek into the lives of the people who made
them. But when did they live? A new way of finding an object’s age now
proves how old the cloth is. Scientists now know they are learning about a
culture that is at least 12,000 years old.
64
A New Kind of Test
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82
94
107
122
135
149
162
173
185
198
209
220
235
248
259
272
For many years, archaeologists did not have a good way to tell how
old their finds were. They could only compare objects found in the
same place and guess that they were from the same time period. Then
in 1947 a scientist named Willard Libby was trying to find out the age of
fossils for a paleontology study. Libby began thinking about a way to get
a more precise age. Libby came up with a theory based on the scientific
fact that living plants absorb a small amount of carbon-14. The amount of
carbon-14 decreases over time. Using logic, Libby inferred that he could
tell how long plants had been dead by measuring how much carbon-14
was left in them. He called this process “carbon dating.” Thanks to Libby,
scientists can be more certain of the age of their discoveries.
In the 1980s, archaeologists first found signs that humans had lived
inside the cave in Peru. They used carbon dating to find the age of bone
and charcoal pieces found in the cave. Those objects all proved to be
around 12,000 years old. This proof was important. The information told
them that humans had visited the mountains near Peru soon after the last
glacier period ended around 12,500 years ago.
Practice • Grade 6 • Unit 6 • Week 4
283
Comprehension and Fluency
Name
More Advanced Dating
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Archaeologists also found bits of
rope and woven thread inside the cave
in Peru. They found finely woven
bits of fabric and bundles of plant
material useful for weaving. From
this find, archaeologists could tell
that an advanced people had visited
the cave. They did not know how old
the samples were, however. Scientists
knew humans had disturbed the cave
at some time. No one knew when. So
no one could say for sure if the bits of
cloth had been left behind 100 years
ago or 12,000 years ago.
The small pieces of cloth had
not been tested with the other cave
samples for a reason. Until lately,
Guitarrero Cave is located in Peru in South
carbon testing was not reliable with
America. Fibers found in the cave were left
behind about 12,000 years ago.
small fragments. Finally, in 2011 a
more advanced method of carbon
dating was used on the bits of fabric. This technique can tell the age of even one
hair. Archaeologists learned at last that the bits of fabric were also 12,000 years
old. Now the scientists knew that prehistoric people had made them.
After learning how old the fabric samples were, scientists were able to learn
more about who visited the cave. Early researchers thought that humans had
gone into the mountains to search for food. Hunters would likely have been men.
From what is known about other cultures, scientists believe that women would
have been the ones to weave the fabric. This suggests that women must also
have gone into the mountains and must have stayed long enough to weave fabric.
Perhaps the men hunted while the women made cloth and rope in the cave.
The latest ways of dating artifacts have led scientists to fresh understandings
of ancient times. Carbon dating has given scientists a way to peer into the past—
sort of like having a telescope on long ago. By finding out when something was
made, scientists can discover more about the time before history was written.
Practice • Grade 6 • Unit 6 • Week 4
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284
Comprehension: Sequence and Fluency
Name
A. Reread the passage and answer the questions.
1. Look at the first paragraph under “A New Kind of Test.” List the
sequence of events that led to Willard Libby’s carbon-dating
process. What signal words help you follow the sequence?
2. About how long after Libby developed the idea of carbon dating did
scientists find signs of humans inside the cave? How do you know?
Copyright © The McGraw-Hill Companies, Inc.
3. List the sequence of the steps that archaeologists took to learn
about the people who lived in the mountain cave in Peru.
B. Work with a partner. Read the passage aloud. Pay attention to
phrasing and rate. Stop after one minute. Fill out the chart.
Words Read
–
Number of
Errors
=
First Read
–
=
Second Read
–
=
Words Correct
Score
Practice • Grade 6 • Unit 6 • Week 4
285
Genre/Text Feature
Name
The Niaux Cave, located in the Pyrenees Mountains in southern France, is
famous for its prehistoric wall paintings. The cave entrance is set high on the
side of a mountain. Scientists believe that because this landscape created a
warm climate, the caves sheltered both animals and humans at the end of the
last Ice Age. In 1906 a series of wall
drawings of three bison, a horse,
and a weasel were discovered in the
main hall of Niaux Cave. In 1971 the
first group of scientists studied the
paintings. A process called radiocarbon
dating was used to identify the age of
the artwork. This process tested the
charcoal used to create the paintings
and confirmed that they were at least
A prehistoric wall painting from the Niaux
Cave in France
14,000 years old.
CAROLUS/Pixtal/agefotostock
The Niaux Cave: Gallery of Prehistoric Art
Answer the questions about the text.
1. List two features of expository text that this text contains.
3. What idea from the text does the photograph help you to visualize?
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Practice • Grade 6 • Unit 6 • Week 4
Copyright © The McGraw-Hill Companies, Inc.
2. What activity is described over a range of time?
Vocabulary Strategy: Greek Roots
Name
A. Read each passage. Look at the meanings of the word parts.
Then write a definition for the word in bold.
1. For many years, archaeologists did not have a good way to tell
how old their finds were.
archaeo = ancient, old; logos = study
2. Then in 1947 a scientist named Willard Libby was trying to find out
the age of fossils for a paleontology study.
paleo = prehistoric; logos = study
3. Finally, in 2011 a more advanced method of carbon dating was used
on the bits of fabric. This technique can tell the age of even one hair.
tech = skill
4. Carbon dating has given scientists a way to peer into the past—
sort of like having a telescope on long ago.
Copyright © The McGraw-Hill Companies, Inc.
tele = far; scope = see
B. Write another word that has each of the following roots. Use a
dictionary if necessary.
1. tele
2. tech
3. ology
Practice • Grade 6 • Unit 6 • Week 4
287
Word Study: Absorbed Prefixes
Name
A. Complete the word equation by adding a prefix to each root
word. Write the new word on the line.
1. im + patiently =
2. ac + commodate =
3. il + logical =
4. ar + rest =
5. ac + company =
6. im + migration =
B. Complete each sentence using the clue in parentheses.
Choose the correct absorbed form of the prefix from the box and
add it to the root word in the clue. Write the word on the line.
Original Prefix and Meaning
Absorbed Forms
ad- means “to” or “toward”
ac-, ar-, at-
in- means “not” or “the opposite of”
im-, ir-, il-
8. The driver made an
(the opposite of legal)
9. I wanted to
school. (to go with as company)
10. My pet dog is a very
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Practice • Grade 6 • Unit 6 • Week 4
sizes. (not regular)
turn and caused an accident.
my friend to the meeting after
puppy! (not mature)
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7. The pieces of paper were
Write About Reading: Write an Analysis
Name
Evidence is details and examples from a text that support a writer’s ideas. The
student who wrote the paragraph below analyzed the author’s use of sequence
to explain a topic.
Topic
sentence
Evidence
Concluding
Statement
By describing steps in order, the author of “Ancient
Threads Reveal Early Weavers” helped me understand the
topic of dating artifacts. I read that a scientist developed
a way to date ancient objects using carbon. With this
method, archaeologists in the 1980s learned that people
lived in caves in Peru about 12,000 years ago. In 2011, an
improved kind of carbon dating helped them prove that
the cave people had woven cloth. Reading the sequence
of events helped me understand what was involved in
identifying the age of the mysterious Peruvian fabrics.
Write a paragraph about the text you have chosen. Cite evidence
from the text to analyze the author’s use of sequence to explain a
topic. Remember to use clear transitions and to use prepositional
phrases correctly.
Copyright © The McGraw-Hill Companies, Inc.
Write a topic sentence:
Cite evidence from the text:
End with a concluding statement:
Practice • Grade 6 • Unit 6 • Week 4
289
Writing Traits: Word Choice
Name
A. Read the draft model. Use the questions that follow the draft
to help you think about how to choose time-order words to show
the sequence of steps in a process.
Draft Model
Marsha wanted to paint her desk. She prepared the area by putting down
newspaper. She sanded the desk. She cleaned the surfaces gently. She let the
desk dry. She started painting.
1. What time-order word or phrase could you use to show the first
thing Marsha did to prepare the area for painting her desk?
2. What time-order words and phrases could you use to clarify the
order of the next three steps Marsha took to prepare the desk for
painting?
3. What time-order word or phrase could you add to identify the last
thing Marsha did in this paragraph?
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Practice • Grade 6 • Unit 6 • Week 4
Copyright © The McGraw-Hill Companies, Inc.
B. Now revise the draft by adding time-order words and phrases
that will help readers better understand the order of steps in the
process described.