Envision Math 6th Grade Textbook Answer Key Topic 1.1 Place Value
Review What You Know
Vocabulary
Choose the best term from the box,
Question 1.
A period placed in a number to separate whole number values from values less than one is called a ? .
Answer:
decimal point
Explanation:
Question 2.
The value of the position of any digit in a number is called its ? .
Answer:
place
Explanation:
Question 3.
The symbols used to write numbers 0, 1,2 3, 4, 5, 6, 7, 8, and 9 are ? .
Answer:
digits
Explanation:
Writing Numbers
Write each word form in standard form.
Question 4.
nineteen
Answer:
19
Explanation:
Question 5.
thirty-seven
Answer:
37
Explanation:
Question 7.
two thousand twelve
Answer:
2,012
Explanation:
Question 8.
forty thousand
Answer:
40,000
Explanation:
Question 9.
one hundred thousand
Answer:
100, 000
Explanation:
Write the word form of each number.
Answer:
See margin
Explanation:
Question 10.
49
Answer:
Question 11.
112
Answer:
Question 12.
10,465
Answer:
Decimals
Writing to Explain Write an answer for the question.
Question 13.
How would you locate 3.33 on the number line? Explain.
Answer:
See margin.
Explanation:
Place Value
How can you read very large numbers?
Answer:
In astronomy, a light-year is the distance that light can travel in one year. One light-year is equal to about 9,500,000,000,000 kilometers. Use a place-value chart to help you find the value of the digit 9 and read the number.
Another Example
What are different ways to write very large numbers?
Answer:
A place-value chart can help you write a very large number, such as 44,600,000,000, in different forms.
Standard form: 44,600,000,000
Word form: forty-four billion, six hundred million
Short word form: 44 billion, 600 million
Expanded form: 40,000,000,000 + 4,000,000,000 + 600,000,000 or
(4 × 10,000,000,000) + (4 × 1,000,000,000) + (6 × 100,000,000)
Explain It
Question 1.
What is the relationship between the commas in a number and the periods in a place-value chart?
Answer:
See margin.
Explanation:
Question 2.
In the example above, how do you know what the addends are for a number written in expanded form?
Answer:
See margin.
Explanation:
You can use the word form to read the number.
Word form: nine trillion, five hundred billion
Guided Practice
Do you know HOW?
In 1 through 4, write the place and value of the underlined digit.
Question 1.
1,234,567
Answer:
See margin.
Explanation:
Question 2.
9,870,563,142,000
Answer:
Question 3.
36,192,748
Answer:
See margin
Explanation:
Question 4.
82,765,432,109,497
Answer:
In 5 and 6, write each number in the form indicated.
Question 5.
57,000,000,009 in expanded form
Answer:
See margin.
Explanation:
Question 6.
321 trillion, 705 thousand in standard form
Answer:
See margin.
Explanation:
Do you UNDERSTAND?
Question 7.
How do you use periods to read and write very large numbers?
Answer:
See margin.
Explanation:
Question 8.
In the example at the top, how would you write the number in expanded form?
Answer:
See margin.
Explanation:
Question 9.
When writing 136,000,000 in expanded form, why would you skip the hundred thousands, ten thousands, thousands, hundreds, tens, and ones?
Answer:
Those places are occupied by zeros.
Explanation:
Independent Practice
In 10 through 12, write the place and value of the digit 3 in each number?
Answer:
See margin.
Explanation:
Question 10.
3,476
Answer:
Question 11.
384,400
Answer:
Question 12.
5,437,200,184,400
Answer:
In 13 through 15, write each number in short-word form.
Answer:
See margin.
Explantion:
Question 13.
18,429,000,050,000
Answer:
Question 14.
10,007,000,000,000
Answer:
Question 15.
8,507,004,041
Answer:
For 16 through 19, use the number 1,435,600,000,000.
Question 16.
What is the place and value of the digit 5? billions,
Answer:
5,000,000,000
Explanation:
Question 17.
What is the value of the digit 3?
Answer:
30,000,000,000
Explanation:
Question 18.
Write the number in word form.
Answer:
One trillion, four hundred thirty-five billion, six hundred million
Question 19.
Using both multiplication and addition, how would you write this number in expanded form?
Answer:
See margin.
Explanation:
Problem Solving
Question 20.
How do you write the number of stars in the Milky Way galaxy in standard form?
Answer:
200,000,000,000
Explanation:
Question 21.
Writing to Explain Describe how you would use the standard form of a number to write the short-word form.
Answer:
See margin.
Explanation:
In a recent year, the world used an estimated 15,850,000,000 kilowatt hours of electricity. Use this information to answer 22 through 24.
Question 22.
What is the value of each non-zero digit in the number
Answer:
10,000,000,000; 5,000,000,000; 800,000,000; 50,000,000
Explanation:
Question 23.
Number Sense From left to right, what is the place of the second 5 in this number?
A. trillions
B. hundred millions
C. ten millions
D. hundred thousands
Answer:
C. ten millions
Explanation:
Question 24.
Algebra At this rate, how many kilowatt hours of electricity might the world use over a 10-year period?
A. 160 million
B. 160 billion
C. 16 trillion
D. 160 trillion
Answer:
B. 160 billion
Explanation:
Question 25.
Which of these numbers represents seventy-six trillion, two hundred seven thousand?
A. 76,000,000,207,000
B. 76,000,000,007,200
C. 76,000,207,000,000
D. 76,000,207,000
Answer:
A. 76,000,000,207,000
Explanation:
Question 26.
Which of these numbers is ten million more than three billion, four hundred twenty-nine million?
A. 3,419,000,000,000
B. 3,439,000,000,000
C. 3,419,000,000
D. 3,439,000,000
Answer:
D. 3,439,000,000
Explanation:
Mixed Problem Solving
Ancient Civilizations in Today’s World
Use the estimated populations shown on the map above to answer 1 through 10.
Question 1.
Which countries have a population in the billions?
Answer:
India and China
Explanation:
Question 2.
Which value does the digit 1 have in Greece’s population?
Answer:
10 million
Explanation:
Question 3.
Which places does the digit 3 occupy in China’s population?
Answer:
Hundred millions, millions, thousands, and ones
Explanation:
Question 4.
Which country has a population close to 80 million?
Answer:
Egypt
Explanation:
Question 5.
Which countries have a population between ten million and one hundred million?
Answer:
Greece, Egypt, and Italy
Explanation:
Question 6.
Draw a place-value chart to show the place and value of each of the digits in I ndia’s population.
Answer:
Place-value chart should show 1,095,351,995.
Explanation:
Question 7.
Which country has the least population? 8. How much less is its population than the greatest population shown?
Answer:
Greece; 1,303,285,655
Explanation:
Question 8.
How many people would India need to gain for its population to equal that of China?
Answer:
218,621,718
Explanation:
Question 9.
In a recent year, the population of Italy’s 10. capital, Rome, was about 2,553,873. About how many times larger was Italy’s population than the population of Rome?
Answer:
About 20 times larger
Explanation:
Question 10.
It is projected that China’s population will increase approximately 20% by 2025. Approximately how many more people will China have?
A. 130,000,000
B. 89,000,000
C. 260,000,000
D. 3,190,000,000
Answer:
C. 260,000,000
Explanation: