To review the use of equivalent fractions in comparisons.
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Teacher’s
Lesson Guide
Key Concepts and Skills
• Find equivalent fractions.
[Number and Numeration Goal 5]
• Compare and order fractions.
[Number and Numeration Goal 6]
• Add fractions with common denominators.
[Operations and Computation Goal 4]
Key Activities
Students rename fractions as equivalent fractions. They compare fractions by renaming them as equivalent fractions with a common denominator. They play Build-It to practice comparing and ordering fractions.
Ongoing Assessment:
Recognizing Student Achievement
Use Mental Math and Reflexes.
[Number and Numeration Goal 6]
Ongoing Assessment:
Informing Instruction See page 620.
Key Vocabulary
Quick Common Denominator (QCD)
Materials
Math Journal 2, pp. 248 and 249
Student Reference Book, pp. 300, 399, and 401
Math Masters, pp. 446 and 447 transparencies of Math Masters, pp. 446 and
447 (optional) 3" by 5" index cards cut in half (optional) red and blue colored pencils or markers scissors straightedge calculator
Math Boxes 8 1
Math Journal 2, p. 250
Geometry Template
Students practice and maintain skills through Math Box problems.
Study Link 8 1
Math Masters, p. 221
Students practice and maintain skills through Study Link activities.
READINESS
Ordering Fractions on a Rope rope or heavy string 8'–10' long 3" by 5" index cards thick marker paper clips
Students make and order fractions on a number line.
ENRICHMENT
Exploring Least Common Multiples
Math Masters, p. 222
Students explore methods for finding least common multiples.
ELL SUPPORT
Building a Math Word Bank
Differentiation Handbook, p. 142
Students define and illustrate the term quick common denominator and identify related words.
For Part 1, have students cut out the 16 fraction cards on Math Masters, page 446 before the lesson.
They will also need to cut Math Masters, page 447 into halves. You can make a transparency of these
Math Masters pages to play the game on the overhead. For the optional Readiness activity in Part 3, hang the string or rope where it will be visible to all students and within their reach during the activity.
Teacher’s Reference Manual,  Grades 4–6 pp. 62, 63, 141, 142
618 Unit 8 Fractions and Ratios

State each fraction and ask students to indicate whether it is closest to the benchmark of 0,
_
, 1, 1 choices. Suggestions:
_
, or 2. Have students use thumbs up to indicate their
_
0
_ _
_
1
_ _
_
1
_
2
_
_
_
1
2
1
_
_
Mental Math and
Reflexes
Use the Mental Math and Reflexes problems to assess students’ ability to compare fractions. Students are making adequate progress if they indicate the correct benchmark for the and fractions.
[Number and Numeration Goal 6]
Complete Problems 1–4 at the top of journal page 248.
1
▶
( Math Journal 2, p. 248; Student Reference Book, p. 399)
WHOLE-CLASS
ACTIVITY
Ask students to compare their answers for the Math Message problems and share how they decided which fraction in each pair is greater. Ask volunteers to share their strategies.
Problem 1 Since the denominators are the same, the wholes are divided into the same number of parts. This means the parts are the same size, so it is easy to compare the number of shaded parts and decide which fraction is greater.
Problem 2 The numerators are the same, but the denominators are not. This means that there are the same number of shaded parts, but the parts are different sizes. The fewer the number of parts that the whole is divided into, the larger each part is. Therefore, the fraction with the smaller denominator is the greater fraction.
Interactive whiteboard-ready ePresentations are available at www.everydaymathonline.com
to help you teach the lesson.
Student Page
Date Time
LESSON
8 1
Comparing Fractions
Math Message
Write < or > . Be prepared to explain how you decided on each answer.
1.
_ < _
2.
>
< means is less than.
3.
_
>
4.
>
_
> means is more than.
Equivalent Fractions
Cross out the fraction in each list that is not equivalent to the other fractions.
5.
2
3
4
6
18
24
20
30
6.
1
4
2
8
4
20
6
24
8
32
7.
3
5
6
10
,
9
20
15
25
Write = or ≠ in each box.
8.
≠
9.
≠ _
≠ means is
not equal to.
10.
= _
11.
≠
Give three equivalent fractions for each fraction.
_
9
_
10
_
_
,
,
_
_
,
,
_
Sample answers:
13.
15.
_
18
_
,
,
_
_
,
,
Fill in the missing number.
_
=
27
19.
12
=
_
_
=
15
17.
_
5
=
12
20.
_
=
3
23.
_
25
18.
=
10
21.
_
20
24.
_
=
36
_
50
Write < or > .
25.
<
26.
<
27.
_ >
28.
>
Math Journal 2, p. 248
248-287_EMCS_S_MJ2_U08_576434.indd 248 2/16/11 1:01 PM
Lesson 8 1 619

Student Page
Student Reference Book, p. 399
Student Page
24
30
6
36
30
36
6
42
6
30
12
30
18
30
6
24
18
24
6
18
12
18
30
42
36
42
6
48
12
42
18
42
24
42
18
48
30
48
24
54
30
54
42
54
48
54
42
48
6
54
12
54
28
35
7
42
35
42
7
49
7
35
14
35
21
35
7
28
21
28
7
21
14
21
35
49
42
49
7
56
14
49
21
49
28
49
21
56
35
56
28
63
35
63
49
63
56
63
49
56
7
63
14
63
8
18
10
18
14
18
16
18
14
16
2
18
4
18
10
14
12
14
2
16
4
14
6
14
8
14
6
16
10
16
2
10
4
10
6
10
6
8
2
8
4
6
2
6
2
4
8
10
2
12
10
12
2
14
12
27
15
27
21
27
24
27
21
24
3
27
6
27
15
21
18
21
3
24
6
21
9
21
12
21
9
24
15
24
3
15
6
15
9
15
3
12
9
12
6
9
3
9
3
6
12
15
3
18
15
18
3
21
1
6
4
5
5
6
1
7
2
5
1
5
3
5
2
3
1
3
1
2
3
4
1
4
1
8
6
7
5
7
3
7
2
7
4
7
5
8
3
8
5
9
4
9
7
9
8
9
1
9
7
8
2
9
16
20
4
24
20
24
4
28
4
20
8
20
12
20
4
8
4
12
8
12
4
16
12
16
20
28
24
28
4
32
8
28
12
28
16
28
12
32
20
32
16
36
20
36
28
36
32
36
28
32
4
36
8
36
Note: The decimals for sevenths have been rounded to the nearest thousandth.
32
40
8
48
40
48
8
56
8
40
16
40
24
40
8
32
24
32
8
24
16
24
40
56
48
56
8
64
16
56
24
56
32
56
24
64
40
64
32
72
40
72
56
72
64
72
56
64
8
72
16
72
Equivalent Fractions, Decimals, and Percents
5
10
6
12
7
14
8
16
9
18
10
20
11
22
12
24
13
26
14
28
15
30
20
25
5
30
25
30
5
35
5
25
10
25
15
25
5
20
15
20
5
15
10
15
25
35
30
35
5
40
10
35
15
35
20
35
15
40
25
40
20
45
25
45
35
45
40
45
35
40
5
45
10
45
36
45
9
54
45
54
9
63
9
45
18
45
27
45
9
36
27
36
9
27
18
27
45
63
54
63
9
72
18
63
27
63
36
63
27
72
45
72
36
81
45
81
63
81
72
81
63
72
9
81
18
81
40
50
10
60
50
60
10
70
10
50
20
50
30
50
10
40
30
40
10
30
20
30
50
70
60
70
10
80
20
70
30
70
40
70
30
80
50
80
40
90
50
90
70
90
80
90
70
80
10
90
20
90
44
55
11
66
55
66
11
77
11
55
22
55
33
55
11
44
33
44
11
33
22
33
55
77
66
77
11
88
22
77
33
77
44
77
33
88
55
88
44
99
55
99
77
99
88
99
77
88
11
99
22
99
48
60
12
72
60
72
12
84
12
60
24
60
36
60
12
48
36
48
12
36
24
36
60
84
72
84
12
96
24
84
36
84
48
84
36
96
60
96
48
108
60
108
84
108
96
108
84
96
12
108
24
108
52
65
13
78
65
78
13
91
13
65
26
65
39
65
13
52
39
52
13
39
26
39
65
91
78
91
13
104
26
91
39
91
52
91
91
104
13
117
26
117
39
104
65
104
52
117
65
117
91
117
104
117
56
70
14
84
70
84
14
98
14
70
28
70
42
70
14
56
42
56
14
42
28
42
70
98
84
98
14
112
28
98
42
98
56
98
98
112
14
126
28
126
42
112
70
112
56
126
70
126
98
126
112
126
60
75
15
90
75
90
15
105
15
75
30
75
45
75
15
60
45
60
15
45
30
45
75
105
90
105
15
120
30
105
45
105
60
105
45
120
75
120
60
135
75
135
105
135
120
135
105
120
15
135
30
135
0.5
0.7
0.8
0.875
0.1
0.2
0.4
0.429
0.571
0.714
0.857
0.125
0.375
0.625
0.2
0.4
0.6
0.8
0.16
0.83
0.143
0.286
0.5
0.3
0.6
0.25
0.75
50%
14.3%
28.6%
42.9%
57.1%
71.4%
85.7%
25%
75%
20%
40%
60%
80%
Student Reference Book, p. 401
620 Unit 8 Fractions and Ratios
Problem 3 Neither the numerators nor the denominators are the same. Use a reference number to compare the fractions.
One fraction is greater than
1
and the other fraction is less than
1
.
Problem 4 Each of the fractions is one fractional part less than a whole. The larger the part is, the smaller the denominator is, and the further away the fraction is from one whole. Therefore, the fraction with the smaller denominator is the lesser fraction.
_
or
_
is greater. The methods outlined above don’t work in this case. A method that does work is to use the Fraction-Stick and Decimal
Number-Line Chart on Student Reference Book, page 399.
Ask a volunteer to explain how to use the chart to determine which fraction is greater. Locate line for
_
_
and
is to the right of the line for
3
5
_
_
on the chart. Since the
, we know that
_
>
_
.
Pose several problems for students to solve with the Fraction-Stick
Chart. Suggestions:
Which is greater?
●
_
or
_ _
● 4
or
_ _
● 2
or
1 2
Watch for students who have trouble isolating the relevant rows when making comparisons on the Fraction-Stick Chart. Have them use a vertical straightedge to find the equivalent decimal for each fraction on the decimal number line. Then compare the decimals or their relative positions. For example, and
_
_
aligns with 0.6
aligns with 0.63; 0.63 is to the right of 0.6, so 0.63 > 0.60, and
_
>
_
.
▶
( Student Reference Book, pp. 399 and 401)
WHOLE-CLASS
ACTIVITY
Ask volunteers to guide the class in the steps for using the
Fraction-Stick and Decimal Number-Line Chart on page 399 to find equivalent fractions for 1 and 2
Then ask students to explain how they would find equivalent fractions without using this chart. The discussion should include the following methods:
Use a multiplication table.
Look up fractions in the table of Equivalent Fractions,
Decimals, and Percents ( Student Reference Book, page 401).
Point out that the first fraction in each row is in simplest form.
Use the multiplication rule. Multiplying the numerator and denominator of a fraction by the same (nonzero) number yields an equivalent fraction.
Example: 2 =
_

Use the division rule. Dividing the numerator and denominator of a fraction by the same (nonzero) number yields an equivalent fraction.
Example:
12
=
_ 4
▶
WHOLE-CLASS
ACTIVITY
Ask students to compare the fractions
2
and
_
and share solution strategies. If the idea is not mentioned, remind students that if two fractions have the same denominator, they only have to compare numerators to tell which is greater. Another approach for comparing fractions is to rename them as equivalent fractions with a common denominator.
Review finding a common denominator and renaming fractions using the Quick Common Denominator (QCD) and the multiplication rule, introduced in Lesson 6-10. The QCD is the product of the denominators you are renaming.
To use this method to compare
2
and
3
5
1.
Find the QCD. 3 ∗ 5 = 15.
2.
Rename
2
:
2
=
_
3.
Rename
_
:
_
=
_ _
Because 10 > 9,
_
>
_
, and
2
>
3
5
Write a few comparison-of-fractions problems on the board or a transparency. Ask students to solve them by renaming the fractions so they have a common denominator.
Suggestions:
●
_
>
_
●
_
>
_
●
●
1
_
<
<
2
_
Ask volunteers to explain their solutions. The QCD can be used for all of the problems, but emphasize that depending on the fractions involved, it might not be the most efficient method for finding a common denominator.
In the first problem, only one of the fractions,
_
, needs to be renamed because 4 is a factor of 8: so 2
=
_ 4 . Since
_
=
4
_
, then
6
9
=
_
3
_
<
5
6
.
=
_
. For the last problem,
_
can be renamed as 2 , and 3 is a factor of 6,
▶
( Math Journal 2, pp. 248 and 249)
PARTNER
ACTIVITY
Ask students to complete journal pages 248 and 249. Circulate and assist.
NOTE
The multiplication method for finding equivalent fractions can be expressed as
_
= n ∗ a b ≠ 0 and n ≠ 0. This does not change the value of the original fraction because multiplying by n n
is equivalent to multiplying by 1.
Student Page
Date Time
LESSON
8
䉬
1
Fraction Review
1. a.
Shade ᎏ
4 of the fraction stick.
b.
Use the fraction stick to find equivalent fractions: ᎏ
4 c.
ᎏ
1 ⫹ ᎏ
1 ⫽
ᎏ
2
4
ᎏ , or ᎏ
1
2
ᎏ
⫽
2
8
⫽
4
16
2. a.
b.
c.
d.
Shade ᎏ
8 of the fraction stick.
Is this more or less than ᎏ
1
2
ᎏ ?
Less than ᎏ
1
2
ᎏ
More than ᎏ
1
4
ᎏ
Is this more or less than ᎏ
1
4
ᎏ ?
ᎏ 3 ⫹ 1 ᎏ ⫽
ᎏ
4
8
ᎏ , or ᎏ
1
2
ᎏ
3.
Joe had 2 granola bars. He ate 1 ᎏ
2 bars. a.
Shade the part that he ate.
b.
Write the part he ate as a decimal.
1.5
4.
Circle the decimal that is equivalent to each fraction. Use your calculator to help you.
a.
ᎏ
1
⫽ b.
ᎏ
1
0
⫽ c.
ᎏ
2 ⫽
0.5
1.10
0.4
0.14
0.1
0.25
0.25
0.010
2.5
1.4
0.50
0.2
5.
Lucy had 16 beads. Half the beads were red. One fourth were blue. The rest were white.
a.
Color ᎏ
1
2
ᎏ of the beads red and ᎏ
4 blue.
b.
What fraction of the beads are white?
c.
Lucy put away all the white beads.
ᎏ
4
, or
What fraction of the remaining beads are red?
ᎏ
8
ᎏ
1
4
ᎏ
, or ᎏ
R
2
3
ᎏ
B
R
B
B
R
R
R
R
R
R
B
Math Journal 2, p. 249
Lesson 8 1 621

Student Page
Games
Build-It
Materials □ 1 Build-It Card Deck ( Math Masters , p. 446)
□ 1 Build-It Gameboard for each player ( Math
Masters, p. 447)
Players 2
Skill Comparing and ordering fractions
Object of the game To be the first player to arrange
5 fraction cards in order from smallest to largest.
Directions
1. Shuffle the fraction cards. Deal 1 card number-side down on each of the 5 spaces on the 2 Build-It gameboards.
2.
Put the remaining cards number-side down for a draw pile.
Turn the top card over and place it number-side up in a discard pile.
3.
Players turn over the 5 cards on their gameboards.
Do not change the order of the cards at any time during the game.
4.
Players take turns. When it is your turn:
♦
Take either the top card from the draw pile or the top card from the discard pile.
♦ Decide whether to keep this card or put it on the discard pile.
♦
If you keep the card, it must replace 1 of the 5 cards on your Build-It gameboard. Put the replaced card on the discard pile.
5.
If all the cards in the draw pile are used, shuffle the discard pile. Place them number-side down in a draw pile. Turn over the top card to start a new discard pile.
6.
The winner is the first player to have all 5 cards on his or her gameboard in order from the smallest fraction to the largest.
Closest to 0
7
12
2
3
3
5
Build-It Card Deck
4
5
3
7
3
8
1
3
11
12
4
7
1
4
7
9
Build-It Gameboard
1
12
3
4
1
5
5
6
Closest to 1
▶
PARTNER
ACTIVITY
( Student Reference Book, pp. 300, 399; Math Masters, pp. 446, 447)
Students cut out the 16 fraction cards from Math Masters, page 446. They cut Math Masters, page 447 in half to create
2 gameboards. Only one set of cards per partnership is needed to play the game, but a gameboard is required for each student.
Go over the rules on Student Reference Book, page 300, and play a practice round with the class. Remind students to use the benchmarks
1
2
and 1 as they consider the placement of fractions and make comparisons with the other fractions on their gameboard. Then have partners play several rounds on their own. Remind students that they cannot change the order of their
5 cards. They replace cards until the fractions are in order from smallest to largest. After students have played Build-It several times, suggest that they play without the game-board. Have students store their fraction cards for future use.
Student Reference Book, p. 300
294_336_EMCS_S_SRB_G5_GAM_576515.indd 300
Have students make their own set of Build-It cards on 3 in. by 5 in. cards that have been cut in half.
A U D I T O R Y K I N E S T H E T I C T A C T I L E V I S U A L
3/8/11 5:13 PM
2
▶
( Math Journal 2, p. 250)
INDEPENDENT
ACTIVITY
Mixed Practice Math Boxes in this lesson are paired with
Math Boxes in Lesson 8-3. The skill in Problem 5 previews Unit 9 content.
Date
LESSON
8 1
Student Page
Math Boxes
1.
Make a circle graph of the survey results.
Favorite After-School Activity
Activity Students
Eat Snack
Visit Friends
Watch TV
Read
Play Outside
18%
35%
22%
10%
15%
Time
Favorite After-School Activity title
35%
18%
15%
10%
22%
126 127
2.
Write each numeral in number-and-word notation.
a.
43,000,000
43 million
b.
607,000
607 thousand
c.
3,000,000,000
d.
72,000
3 billion
72 thousand
3.
True or False? Write T or F.
a.
A square is also a rectangle.
T
b.
Some trapezoids are rectangles.
c.
All kites are quadrangles.
d.
A rhombus is not a parallelogram.
F
T
F
4 146
4.
Complete the “What’s My Rule?” table and state the rule.
in out
3
15 Rule out = 5 ∗ in 8
2
40
1
10
50
4 20
5.
Find the area of the rectangle.
Area = b ∗ h
14 cm
Area:
112 cm
2
(unit)
231 232 189
Math Journal 2, p. 250
248-287_EMCS_S_MJ2_G5_U08_576434.indd 250 3/16/11 2:29 PM
▶
( Math Masters, p. 221)
Home Connection Students practice comparing fractions.
Remind students that they can decide which fraction is greater by using the strategies discussed in the lesson such as comparing each fraction to
1
or finding the Quick Common
2
Denominator. Students also find decimal equivalents for fractions.
3
READINESS
▶
INDEPENDENT
ACTIVITY
SMALL-GROUP
ACTIVITY
5–15 Min
To provide experience with ordering fractions, have students order fractions on a number line. Ask each student to write a fraction greater than 0 and less than 1 on a 3 in. by 5 in. card. Consider assigning denominators to small groups and having them compare their numerators in the groups to avoid duplications.
622 Unit 8 Fractions and Ratios

Students link two paper clips together and attach their card to it.
They go to the number line string one (or a few) at a time to hang their fractions in order, between 0 and 1. Do not worry about spacing. It is more important that the fraction cards be placed in the correct order. The task will become more difficult as additional fractions are added to the string. If two fractions are equivalent, clip the fraction cards together as illustrated.
0 1
9
1
8
3
8
1
2
3
5
6
8
3
4
7
8
1
ENRICHMENT
▶
( Math Masters, p. 222)
PARTNER
ACTIVITY
15–30 Min
To apply students’ understanding of equivalent fractions, have them explore finding the least common multiple of two or more numbers. Students find the least common multiple by making lists and using the prime factorization of numbers. When students have completed the page, have them solve the following problems:
● 4
+
_
+
1 _ _
●
_
+
_ _
, or 1
_
● 11
+
22
, or 1
_
In the third problem, the least common multiple and the quick common denominator are the same. Ask volunteers to share how they decide on a method to find common denominators. Sample answer: Choose the most efficient method depending on the numbers. With smaller numbers or by first using prime factorizations, you can do the computations faster, because you can do much of it mentally.
ELL SUPPORT
▶
( Differentiation Handbook, p. 142)
SMALL-GROUP
ACTIVITY
15–30 Min
To provide language support for fraction concepts, have students use the Word Bank Template found on Differentiation Handbook, page 142 . Ask students to write the term quick common denominator, draw pictures relating to the term, and write other related words. See the Differentiation Handbook for more information.
Study Link Master
Date Time Name
STUDY LINK
8
䉬
1
Comparing Fractions
Circle the greater fraction for each pair.
1.
3
ᎏ or ᎏ
6
4.
ᎏ
0 or ᎏ
8
2.
2
ᎏ
5.
ᎏ
1 or ᎏ
2
9
ᎏ or ᎏ
7
3.
4
ᎏ or ᎏ
5
6
ᎏ
6.
ᎏ
7
ᎏ or ᎏ
1
66 – 68
83 – 88
7.
Explain how you got your answer for Problem 5.
Sample answer: The quick common denominator is
21
ᎏ
9
ⴱ
⫽
17, or 357.
ᎏ
2
2
1
1
⫽
ᎏ
8
1 1
3 5 7
⫽
. So
ᎏ
ᎏ
9
ⴱ
ⴱ
1
1
7
7
⫽
ᎏ
7
, and is greater.
Write the decimal equivalent for each fraction.
8.
ᎏ
4
ᎏ ⫽
11.
1
ᎏ ⫽
0.75
0.7
9.
ᎏ ⫽
12.
1 1 ⫽
0.6
0.55
10.
ᎏ
8
ᎏ ⫽
13.
2 1 ⫽
0.625
0.84
14.
Explain how you can do Problem 10 without using a calculator.
Sample answer: so ᎏ
5
8
ᎏ ⫽ ᎏ
4
8
ᎏ ⫹ ᎏ
1
8
ᎏ ⫽
ᎏ ᎏ is half of
0.5 ⫹
ᎏ
1
4
ᎏ (0.25 ⫼ 2 ⫽
0.125, or 0.625.
0.125),
Use ⬎ , ⬍
15.
ᎏ
2
ᎏ
18.
1
⫹ ᎏ
5
, or ⫽
⬎
⬎ to make each number sentence true.
1
ᎏ
⫹
1
ᎏ
5
16.
ᎏ
19.
1
⫹ 2
ᎏ
⬎
⫽
3
ᎏ
⫹
1
ᎏ
4
17.
ᎏ
9
ᎏ
20.
1
⫹ ᎏ
3
⬎
⬎
ᎏ
6 ⫹
1
1
ᎏ
21.
Explain how you found the answer to Problem 20.
Sample answer: so ᎏ
6
7
ᎏ ⫹ ᎏ
1
8
ᎏ
6
ᎏ
⫹
ᎏ
1
7
ᎏ is less than 1.
⫽
1.
ᎏ
1
8
ᎏ is less than ᎏ
1
7
ᎏ ,
22.
24.
Practice
675 ⴱ 42 ⫽
67.5
⫺
0.42
⫽
28,350
67.08
23.
25.
28,350 ⫼ 675 ⫽
28,350
⫹
42
⫹
67.08
⫽
42
28,459.08
Math Masters, p. 221
Name
LESSON
8
䉬
1
Teaching Master
Date Time
Exploring Least Common Multiples
One way to find a common denominator is to use the least common multiple.
The LCM is the smallest number that is a multiple of the given denominators.
You can find the least common multiple by making lists of multiples.
Find the least common multiple for ᎏ
9
, ᎏ
5
6
ᎏ , and ᎏ
1
4
ᎏ . List the multiples of each denominator.
䉬 Multiples of 9:
9, 18, 27, 36, 45, …
䉬 Multiples of 6:
6, 12, 18, 24, 30, 36, …
䉬 Multiples of 4:
4, 8, 12, 16, 20, 24, 28, 32, 36, …
䉬 Least common multiple:
36
Another way to find the least common multiple is to use prime factorization.
8
6
2 º 4
Find the least common multiple for 8 and 6.
2 º 3
Step 1 Use factor trees to find the prime factorization.
2 º 2 º 2
Step 2 Count the appearance of each different prime number.
Note only the largest counts.
䉬
䉬
2 appears 3 times in the prime factorization of 8.
3 appears once in the prime factorization of 6.
Step 3 Write a multiplication expression using these counts.
䉬 2 ⴱ 2 ⴱ 2 ⴱ 3 ⫽ 24 so 24 is the least common multiple of 8 and 6.
Use the prime factorization method to find the LCM.
1.
9, 6, and 4 2.
20 and 90 3.
15 and 49 4.
12, 15, and 25
5.
What might be an advantage or disadvantage to using the prime factorization method to find the least common multiple?
Answers vary.
Math Masters, p. 222
Lesson 8 1 623