Transcript Multiplying and Dividing of Fractions

Multiplying and Dividing of Fractions
Section 3.4 Pages 123 – 129
Section 3.5 Pages 130 – 136
Multiplying Simple Fractions- Finding the
Product
 To multiply two simple fractions, complete the following
steps.
 1. Multiply the numerators.
 2. Multiply the denominators.
 3. Reduce the product.
 4. Identify the resulting sign on the question ( -/+)
Example
6
2
3 2 3 2


 
5  3 15 5
5 3
Try ME:
 5   2
    
12
9
 8   4
     
12
7
Multiplying a Whole Number and a Fraction –
Finding the Product
 To multiply a whole number and a fraction,
complete the following steps.
 1. Convert the whole number to a fraction.
 2. Multiply the numerators.
 3. Multiply the denominators.
 4. Reduce the product.
 5. Identify the resulting sign ( -/+)
Try ME:
 3
2 
 4
7
 3
8
What about multiplying mixed
numbers?
 If a question contains a mixed number, simply
convert it to an improper fraction and…
 1. Multiply the numerators.
 2. Multiply the denominators.
 3. Reduce the product.
 4. Identify the resulting sign ( -/+)
Try ME:
 2  5
 6   1 
3
6
 2  5
 2   3 
5
9
Multiplying Rational Numbers in Decimal form
 1. Predict the sign ( +/-)
 2. Using compatible numbers to solve the
question
 3. Place the correct number of decimal places
into your product
Try ME:
(-0.4)( -0.7)
(0.5)(- 2.4)
Dividing Simple Fractions- Find the Quotient
 To divide one fraction by a 2nd fraction, keep,
change the division sign to multiplication, and
flip the 2nd fraction.
 1. Change the 2nd fraction to its reciprocal
 2. Multiply the numerators.
 3. Multiply the denominators.
 4. Reduce the quotient.
 5. Identify the sign result of the question (+/-)
Try ME:
 3  6 
     
2
7
 7  9
      
9
4
Dividing Fractions with Mixed
Numbers
 To divide a fraction by a mixed number:
 1. Convert the mixed number to an improper
fraction.
 2. Keep, Change, Flip!
 3. Follow rules for multiplying fractions.
Just like in multiplication, convert all
mixed numbers to improper fractions
before dividing!
Try ME:
 3  5 
 3    2 
5
6
9
 1 
 6    2 
2
10