1. Dividing Fractions
By: Greg Stark

2. Division
A basic rule of math – if you multiply the dividend (the number being divided) and the divisor (the number you are dividing by) by the same factor, the answer will not change 4 2 2 ÷ = 4 2 = 8 4 2 ÷ ÷ =
X 2
X 2 4 2 = 20 10 2 ÷ ÷ =
X 5
X 5

3. Division
What is the easiest number to divide by?
A basis rule of math – dividing by 1 does not change the value of number 4 1 4 ÷ = 2 1 2 ÷ =
326 1
326 ÷ =

4. 3 1 3 Division by a Fraction ÷ ÷ ÷ = ÷ = 3 4 1 4 3 4 4 1 \ 1 4 4 1 \ x
How can we use this information to divide by one?
A basic rule of math – if we multiply a number by it’s inverse, the product is one 1 1 3 4 1 4 3 4 4 1 \ 1 4 4 1 \ ÷
÷ 4 ÷
÷ 4 x x \ \
÷ 4
÷ 4 1 1 1 3 1 1 3 1 ÷ 3 = ÷ = 2 3

5. Dividing a Fraction by a Fraction
Another example: 1 1 1 2 3 2 7 2 3 \ 7 2 2 7 \ 7 2 \ ÷
÷ 2 ÷
÷ 2
÷ 7 x x \ \ \
÷ 2
÷ 7
÷ 2 1 1 1 7 3 1 3 2 =

6. Dividing a Whole Number by a Fraction
For example: 1 1 2 5 1 2 1 1 2 2 1 \ 5 ÷ ÷
÷ 2 x x \
÷ 2 1 10 1 10 =

7. Dividing Mixed Numbers
In order to divide with fractions, both factors must be in the form of fractions
To convert a mixed number into a fraction, multiply the whole number by the denominator of the fraction, then add the product to the numerator 1 5 2 3 13 25 21 5 5 3 21 5 3 5 63 25 4 ÷ 1 2 = ÷ x = = =

8. Review: Dividing with fractions
Ensure all values are fractions, before you beginning the division process
To convert a whole number to a fraction, place it over 1.
To convert a mixed number to a fraction, multiply the whole number by the denominator of the fraction, then add the product to the numerator
Invert the divisor - the fraction you are dividing by – and multiply the fractions together
Reduce the product to lowest terms