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Fractions with
different denominators
can be compared
by changing them to an
equivalent fraction with a common denominator.
A Common Denominator
is when two fractions have the
same denominator.
To
start: Find the
Least
Common Multiple
(LCM)
of your two denominators.
Ex: 3/4
compared to 2/3
4= 4, 8, 12,
16, ...
3= 3, 6, 9, 12
12 is the LCM
3
x3/4
x3
= 9/12
2
x4/3
x4
= 8/12
so...
3/4
can also be 9/12
and
2/3
can also be 8/12
Then:
Compare
the
NEW
numerators (top number of fraction)
to determine < , > , =
9
is greater (>) than
8
so...
9/12
> 8/12
or
3/4
> 2/3
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Example 1:
2/5
compared to
3/4
5= 5, 10, 15,
20, 25, ...
4= 4, 8, 12, 16, 20
LCM= 20
2
x4/5
x4
= 8/20
3
x5/4
x5
= 15/20
8 < 15, so...
8/20 <
15/20, or
2/5
< 3/4
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Example 2:
1/2
compared to
4/7
2= 2, 4, 6,
8, 10, 12, 14,
16...
7= 7, 14
LCM= 14
1
x7/2
x7
= 7/14
4
x2/7
x2
= 8/14
7 < 8, so...
7/14 <
8/14, or
1/2
< 4/7
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Example 3:
3/5
compared to
2/3
5= 5, 10, 15,
20, ...
3= 3, 6, 9, 12,
15
LCM= 15
3
x3/5
x3
= 9/15
2
x5/3
x5
= 10/15
9 < 10, so...
9/15 <
10/15, or
3/5
< 2/3
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Upon further review:
Fractions
that have different denominators
can be compared
Find the Common
Denominator
of the two fractions
by finding their LCM
(Least Common Multiple)
Then compare the numerators
to see which is < , > , =
Let's
Practice
or
NYS Test Prep Questions
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