MSM07G6_RESBK_Ch05_011-018.pe
1/11/06
3:28 PM
Page 16
Name
LESSON
Date
Class
Problem Solving
5-2 Adding and Subtracting with Unlike Denominators
Use the circle graph to answer the questions. Write each
answer in simplest form.
1. On which two continents do most
people live? How much of the total
population do they make up together?
World Population, 2001
1
25
1
10
2
25
Asia and Europe; 18 of the
25
3
50
population
3
5
2. How much of the world’s population
live in either North America or South
America?
3
25
7
of the population
50
Africa
North America
South America
Europe
Asia
Other
3. How much more of the world’s total
population lives in Asia than in Africa?
1
of the population
2
Circle the letter of the correct answer.
4. How much of Earth’s total population
do people in Asia and Africa make up
all together?
5. What is the difference between North
America’s part of the total population
and Africa’s part?
3
A 10 of the population
1
F Africa has 嘷
50 more.
2
B 5 of the population
G Africa has 50 less.
7
C 嘷
10 of the population
H Africa has 50 more.
7
D 5 of the population
J Africa has 50 less.
1
9
9
6. How much more of the population
lives in Europe than in North
America?
7. How much of the world’s population
lives in North America and Europe?
1
of the population
F 25
1
of the population
A 2
嘷
5
1
B 5 of the population
1
C 1
of the population
5
1
D 1
of the population
0
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
1
of the population
G
15
1
H 5 of the population
嘷
1
of the population
J 20
16
Holt Mathematics
MSM07G6_RESBK_Ch05_083-102.pe
1/11/06
3:33 PM
Page 86
Problem Solving
5-2 Adding and Subtracting with Unlike Denominators
Challenge
5-2 Egyptian Fractions
LESSON
LESSON
Use the circle graph to answer the questions. Write each
answer in simplest form.
Did you know that ancient Egyptians used fractions 5,000 years
ago? Some of their fractions were like the ones we use today.
However, the Egyptians only used unit fractions, or fractions with a
numerator of 1. All other fractions had to be written as a sum of unit
fractions. And no sum could repeat the same unit fraction! For
3
1
1. On which two continents do most
people live? How much of the total
population do they make up together?
1
example, the Egyptians would write 4 as 2 4. They would not
1
1
1
write 4 4 4.
1
25
1
10
2
25
Asia and Europe; 18 of the
25
3
50
population
Ancient Egyptians did not have paper. They recorded their
math work on papyrus, or thin strips of dried plants. Study the
Egyptian fractions recorded on the papyrus scrolls below. Then
write each fraction the way we do today.
3
5
2. How much of the world’s population
live in either North America or South
America?
3
25
7
of the population
50
1.
2
3
1
1
2
6
World Population, 2001
Africa
North America
South America
Europe
Asia
Other
3. How much more of the world’s total
population lives in Asia than in Africa?
1
of the population
2
2.
Circle the letter of the correct answer.
4. How much of Earth’s total population
do people in Asia and Africa make up
all together?
4
5
1
1
1
2
4
20
3.
5
6
1
1
2
3
5. What is the difference between North
America’s part of the total population
and Africa’s part?
3
A 1
0 of the population
1
F Africa has 嘷
50 more.
1
2
B 5 of the population
G Africa has 50 less.
7
C 1
嘷
0 of the population
H Africa has 50 more.
7
D 5 of the population
J Africa has 50 less.
9
9
4.
7. How much of the world’s population
lives in North America and Europe?
6. How much more of the population
lives in Europe than in North
America?
3
8
1
1
4
8
1
F 2
of the population
5
1
of the population
A 2
嘷
5
9
10
1
1
1
2
3
15
1
of the population
G 1
5
1
B 5 of the population
5.
1
H 5 of the population
嘷
1
C 1
of the population
5
1
J 2
of the population
0
1
D 1
of the population
0
15
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
Holt Mathematics
LESSON
1
1
You can use fraction bars to show 2 and 3
Decide whether each statement is true or false. Circle
your answer.
1
3
Use the letters of your true answers and rearrange them
to answer the question.
These fractions have denominators that are different. They are
called unlike fractions.
To add or subtract unlike fractions, the denominators must be the
same. They must have a common denominator.
1 1 1
6 6 6
Holt Mathematics
Puzzles, Twisters & Teasers
5-2 The Truth of the Matter
Reading Strategies
5-2 Use Fraction Bars
LESSON
1
2
16
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
1. one-third plus one-seventh is greater than one-half
E false
嘷
M true
7
3
1
1
10
21
21
3
7
21
1 1
6 6
2. one-fourth plus one-ninth is greater than one-third
C true
嘷
1
1
The common denominator for 2 and 3 is 6.
P false
9
4
1
1
13
36
36
4
9
36
To get a common denominator for two fractions, multiply the
denominators.
halves • thirds sixths, or 2 • 3 6
3. four-fifths minus one-third is less than one-half
D true
嘷
N false
4
1
12
5
7
5
3
15
15
15
1. What are unlike fractions?
4. three-fourths minus three tenths equals one-half
Fractions that have different denominators.
S false
嘷
A true
2. If you want to add or subtract unlike fractions, what do you need
to do?
3
3
15
6
9
4
10
20
20
20
5. seven-twelfths plus three-eighths is greater than one
Find a common denominator.
1
1
3. How do you get a common denominator for 2 and 3?
T false
嘷
J true
7
9
3
14
23
12
24
8
24
24
Multiply the denominators.
6. three-fourths minus three-twelfths equals one-half
4. How many sixths are in one-half?
L true
嘷
B false
3
9
3
6
3
1
12
12
12
12
4
2
three
5. How many sixths are in one-third?
What must you find in order to add or subtract unlike fractions?
two
The
6. What is the sum of one-half and one-third?
L
C
D
5
6
7. What is the difference between one-half and one-third?
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
17
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
1
6
Holt Mathematics
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
86
18
Holt Mathematics
Holt Mathematics