Transcript Multiplying Fractions

Multiplying and Dividing
Fractions and Mixed
Numbers
Today you will learn to:
• multiply fractions and mixed numbers.
• divide fractions and mixed numbers,
M07.A-N.1.1.3: To apply properties of operations to multiply
and divide rational numbers, including real-world contexts.
Warm-up Problem: Multiplying
Fractions
A paper published in a
medical journal reported that
about 11/25 of girls ages 16 to
17 do not exercise at all. The
entire study consisted of
about 2,500 girls. About how
many did not exercise?
Multiplying Fractions
When multiplying fractions and mixed
numbers, you do not need a common denominator as
you do when adding and subtracting fractions and
mixed numbers. To multiply fractions, you multiply
their numerators and multiply their denominators,
then simplify (if necessary).
Multiplying a Fraction by a Whole
Number
To multiply a fraction by a whole number,
write the whole number as a fraction with a
denominator of 1.
Multiplying Mixed Numbers
To multiply mixed numbers, first write them
as improper fractions, and then multiply as you do
with fractions.
Dividing Fractions
To divide by a fraction, multiply by its
reciprocal. Two numbers are reciprocals if their
product is one. For example, the fractions 2/6 and
6/2 are reciprocals.
To find the reciprocal of a fraction, interchange
the numerator and denominator.
Dividing Mixed Numbers
To divide mixed numbers, rewrite them as
improper fractions.