1. Rational Numbers & Equations
Lesson 4
Rational Numbers & Equations
Multiplying and Dividing Fractions

2. Warm-Up

3. Multiplying and Dividing Fractions
Target:
Multiply and divide fractions.

4. Vocabulary
Reciprocal: Two numbers are reciprocals if their product is 1. To find a reciprocal, “flip” the fraction so the numerator becomes the denominator and the denominator becomes the numerator.

5. Multiplying Fractions
For any numbers a, b, c and d:

6. For any numbers a, b, c and d :
Dividing Fractions
For any numbers a, b, c and d :

7. Example 1 Find the value of using models. Shade vertically.
Shade horizontally.
The answer is the number of regions that are shaded twice.
Put the answer in simplest form.

8. Example 2
Find the value of
Multiply.
Simplify.

9. Example 3
Find the value of
Divide.
Simplify.

10. Example 4 Find the value of . Divide. Simplify.
Change to a mixed number.

11. Exit Problems
Find each product or quotient. Write answers in simplest form.

12. Communication Prompt
Fractions can be simplified before or after multiplying.
Which method do you prefer and why?