In this lesson, you will expand your skills in fraction division. You will learn that dividing by a number and multiplying by the reciprocal of the number give the same result. Make sure you always rewrite the division problem as a multiplication problem before you try to find common factors or cancel out factors.
Look at the following problems and simplify:
Both are equal to 2.
What is the relationship between 5 and 
? Let’s multiply them and find out!
Now do you see what the rule “Keep, Change, Flip” means?
When you divide fractions, you are multiplying by the reciprocal to get your answer.
- Keep the first number (dividend)
- Change division sign to multiplication
- Flip (or invert) the second fraction
When you divide mixed numbers, follow these steps:
- Change the mixed number to an improper fraction
- Keep the first number
- Change division sign to multiplication
- Flip (multiply by the reciprocal)
- Simplify
(source)