Multiply Fractions by Fractions
8-1
Ms. Amazing is a great magician.
She can take a red rope that is
^3
8
yd long and change ^2
3
of it
into a blue rope. How long is the
blue part of the rope?
To find how long the blue part of the rope, n, is,
multiply:
2
3
3
8 ydn.
To multiply a fraction by a fraction:
Multiply the numerators.
Then multiply the denominators.
Write the product in simplest form.
The blue part of the rope is ^14 yd long.
You can also use the greatest common factor
(GCF) to multiply a fraction by a fraction.
Divide anynumerator and
denominator by their GCF.
Multiply the numerators.
Then multiply the denominators.
The product will be in simplest form.
^23 ^38 ^23 ^38
^23 ^38 264 2.^64 . 66 ^14
1 1
^23 ^38 ^23 ^38
1 4
^11 ^14
1
4
simplest form
GCF of 2 and 8: 2
GCF of 3 and 3: 3
simplest form
Study these examples.
2 1
145 ^56 145 ^56
3 3
2
3
1
3
2
9
simplest form
1
8
2
3
2
8
4
8
6
8
3
8
0 5
8
7
8
8
8
Draw a diagram to illustrate .
Then write a multiplication sentence.
32 ^34 126 ^12
3
4
2 3 2 3 3 4
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