Chapter 1
Lesson
Vocabulary
Numbers in
Everyday Use
1-1
decimal system
decimal notation
whole numbers
ordinal numbers
Applications of whole numbers are found
everywhere and written most commonly in base 10.
BIG IDEA
Mental Math
Calculate.
Whole Numbers
a. 99 + 100 + 101
The decimal system, also called the base 10 system, is a system
of writing numbers based on the number ten. A number written in
the decimal system is said to be in decimal notation. In decimal
notation, the numbers zero, one, two, three, … , which we write in
decimal form as 0, 1, 2, 3, … , 20, 21, … , 99, 100, 101, … ,
are called the whole numbers. You can add 1 to any whole
number to get the next one. Thus, whole numbers go on
forever. Notice that we call the whole numbers decimals
even though there are no decimal points.
b. 397 + 400 + 403
c. 1,010 + 1,000 + 989
Africa
Guinea
According to one estimate, there were nine million, four
hundred fi fty-two thousand, six hundred seventy people
living in Guinea on April 26, 2005. We could write this in
decimal form as 9,452,670 people. Each digit has a place
value. Here are the place values for the seven digits of the
number that represents this population.
ds
an s
s
ou nd
th usa ds s
d
s
n e o an ed
io dr th s dr
s
ill un en hou un ens ne
o
h t
t
m h t
9, 4 5
Conakry
“Quiz Yourself” (QY) questions are designed to help you follow
the reading. You should try to answer each Quiz Yourself question
before reading on. An answer is found either in the reading after
the question or at the very end of the lesson. See Quiz Yourself 1
at the right.
6
Guinea
2, 6 7 0
QUIZ YOURSELF 1
If the population of
Guinea increased by thirty
thousand, what would the
new population be?
Reading and Writing Numbers
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Lesson 1-1
Some Uses of Numbers
Counts and Counting Units
The population of Guinea, 9,452,670, is an example of a count. The
most basic use of numbers is as counts. For every count there is a
counting unit. The counting unit for the population of Guinea is
“people.” Counts are always whole numbers; they are never negative
numbers or fractions between whole numbers.
Identifications and Codes
A student or employee ID number shows how whole numbers can
be used as an identification or a code. ZIP codes also identify. For
instance, the ZIP code below identifies the village of Wilmette, in the
state of Illinois.
Wilmette Post Office
99 Post Office Lane
Wilmette, IL 60091
Midwest
Northeast IL
(IL, KS, MO, NE)
Wilmette,
IL
Ordering
Whole numbers can also be used for ordering. This order is usually
found by counting. For instance, in 2006 the Pittsburgh Pirates
finished in fi fth place in the National League Central Division. The
word “fi fth” indicates that four teams finished ahead of the Pirates.
Because of this, the words first, second, third, fourth, … , are called
ordinal numbers.
See Quiz Yourself 2 at the right.
Other Uses of Whole Numbers
QUIZ YOURSELF 2
What ordinal number
corresponds to the whole
number 12?
Whole numbers can be used in other ways. Here are some examples.
Measures
Ayana spent $5 on lunch yesterday.
Comparisons
The Lugnuts scored 4 times as many runs as
the Cougars.
Locations
The school is at 55 Maple Street.
Scores
Miranda scored 95 on the last test.
Many uses of numbers require more than just the whole numbers.
You will find some of these other uses in the following activity. They
are also described in the next two lessons.
Numbers in Everyday Use
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Chapter 1
Activity
Pick one page from a daily or weekly newspaper.
Find every number on the page, including those in
advertisements. (Remember that some numbers
may be written as words.) You may wish to
highlight or circle each number you find.
1. How many numbers did you find on your page?
(You may have to estimate.)
2. How many numbers were written in words?
In 3–9, find five examples of each usage of
numbers on your page (or on other pages). You
may find that some of your numbers are used in
more than one way.
Tuesday
15 Main St.
Stanton
555-123-4567
Hours:
Monday Closed,
Tues., Wed., Fri. 6-6
Wed. eve hours
Reopening 6:30-9
Thurs. 6-7 • Sat. 6-5
Our commitment
to you:
Quality
& Fast
Service!
3. used as counts
6. used to indicate order or rank, for example,
“first”
7. used as measures
8. estimates
In Stanton
“Our generations of family serving
your generations of family.”
DID YOU KNOW...WE HAVE
8 Barber Chairs/10 Barbers
Serving the Community Since 1992
Private Parking Lot
Family Atmosphere
Children & Senior Discounts
50% off your fourth haircut
The Best Around
4. used as identifications or codes
5. used as locations, such as addresses or times
November 28, 2006
moved here, there was
one gas station that also
served as a general store.
Now there are 24-hour
convenience stores and
three times as many restaurants as there used to be.
Most residents have appre-
walked nearly daily for
over seven years. “I’ve
lived on 5th Street since
1984. I’ve watched new
two- and three-story houses
go up, and seen lots of
young families move in. It’s
been really nice.”
9. used in other ways
Questions
COVERING THE IDEAS
Use these questions to check your understanding of the ideas of the
lesson. If you cannot answer a question, you should go back to the
reading for help. For this lesson, the reading includes the first pages
of the chapter.
1. What people invented the decimal system?
2. About when did the Mayas invent a symbol for 0?
3. a. Who was Fibonacci?
b. What did he do that relates to the decimal system?
c. When did he do it?
4. Name two different ways that numbers are used.
5. Name four different ways that numbers are written.
8
Reading and Writing Numbers
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Lesson 1-1
6. What is the smallest whole number?
7. Name the digit in each indicated place value of the number
2,408,391.
a. hundred thousands
b. hundreds
c. thousands
d. ones
8. Name something for which the count is between one million and
ten million.
9. Give an example of a whole number other than an ID number or
a ZIP code that is used for identification.
10. Give an example of a whole number that is used for ordering.
11. Give an example of a whole number that is used to measure.
APPLYING THE MATHEMATICS
These questions extend the content of the lesson. You should study
the examples and explanations if you cannot get an answer. For some
questions, you can check your answers with the ones in the back of
this book.
12. A person buys four dozen eggs.
a. Name the count.
b. Name the counting unit.
13. One of the books of the Jewish and Christian scriptures is called
Numbers because it begins with a census of the adult males of
the Tribes of Israel. The ancients did not have our numerals, so
they wrote out the population in words. One part of this book is
translated as follows: “… of the tribe of Gad, were forty and five
thousand six hundred and fi fty.” Write this number in base 10.
14. Federal aid is often given on the basis of population. The greater
the population, the greater the aid. Use the table below that
shows the populations of some metropolitan areas as tallied by
the U.S. Census Bureau in 2000.
Metropolitan Area
Population
Grand Rapids/Muskegon/Holland, MI
1,088,514
Louisville, KY
1,025,598
Oklahoma City, OK
1,083,346
Rochester, NY
1,098,201
a. Which of the metropolitan areas would get the most aid?
b. Which of the metropolitan areas would get the least aid?
15. Tell why the counts in Question 14 were estimates, even on the
day they were made.
Numbers in Everyday Use
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Chapter 1
16. In this lesson, you have seen seven different uses of whole
numbers. Write a short paragraph (five to seven sentences) in
which you use whole numbers in at least five different ways.
17. Write a set of directions to go from the front door of your school
to the school library without using any numbers.
REVIEW
Every lesson contains review questions to practice ideas you have
studied earlier.
18. Calculate. (Previous Course)
a. 5 × 5 × 5
b. 5 × 5 × 5 × 5
19. Graph the numbers 10, 2, and –6 on a number line.
(Previous Course)
EXPLORATION
These questions ask you to explore mathematics topics related to the
lesson. Sometimes you will need to use references found in a library
or on the Internet.
20. The country of Guinea, mentioned in
this lesson, has a total land area of
95,000 square miles.
a. What U.S. state has a population
closest to that of Guinea?
b. Is the land area of this state smaller or
larger than the land area of Guinea?
c. Is the population of this state more
or less dense than the population
of Guinea?
21. You may have seen a game or a piece of software labeled
something like “Version 5.2.” Your best friend argues that the
number 5.2 is not a count because 5.2 is not a whole number.
However, your sister is not convinced because she thinks that
before Version 5.2, there were versions 5.0 and 5.1. With whom
do you agree? Explain your thinking.
This Guinean fisherman is
repairing a fishing net.
QUIZ YOURSELF ANSWERS
1. 9,482,670
2. twelfth
10
Reading and Writing Numbers
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