Fraction Multiplicationand Division

Algebra Seminar2012-2013

Fraction Multiplication• Here are some fraction multiplication

examples.• Can you tell how to multiply fraction

from these examples?

Multiplying Fractions Together

1.) Multiply numerator by numerator straight across the top of the fractions.

2.) Multiply denominator by denominator straight across the bottom of the fractions.

Practice

What if our fraction is in the form of a mixed number?

• Because of the order of operations, mixed numbers cannot be multiplied.

• Change mixed numbers to improper fractions, then multiply.

Some to try.1. Change any whole or mixed numbers to improper fractions.2. Multiply straight across.3. Simplify answers.

Fraction Division

(Opposite of Multiplication)

Dividing two fractions is the same thing as multiplying by the reciprocal:

To find the reciprocal of a

fraction you flip the numerator and

denominator

Dividing Fractions Example• Keep the first fraction the same.• Change the division sign to

multiplication.• Use the reciprocal of the second fraction.• Then multiply!

Tanner had a pizza and was planning to eat one-fourth of the pie. Jackson came over and Tanner was nice enough to divide his quarter in 2. How much of the pizza did each person get?

Dividing Fractions with Mixed Numbers

• Remember! We cannot multiply mixed numbers.

• We must change them to improper fractions first!

Some More Practice

Levi made fudge this weekend. He wants to put 5 1/3 lbs of chocolate into separate containers. Each container holds 2/3 lb. How many containers will he need?