1. Multiplying and Dividing Fractions
Chapter 2
Multiplying and Dividing Fractions

2. Multiplying Fractions and Mixed Numbers
2.4
Multiplying Fractions and Mixed Numbers

3. Multiplying Fractions
To multiply two fractions, multiply the numerators and multiply the denominators.
If a, b, c, and d represent positive whole numbers we have
Objective A 3

4. Examples
Multiply. a. b. c.
Objective A 4

5. Examples
Multiply and simplify. a. b.
Objective A 5

6. Multiplying Fractions and Mixed Numbers or Whole Numbers
Multiplying Fractions and Mixed Numbers of Whole Numbers
To multiply with mixed numbers or whole numbers, first write any mixed or whole numbers as fractions and then multiply as usual.
Objective A 6

7. Examples
Multiply. a. b.
Objective A 7

8. Example
Multiply.
Objective A 8

9. Example Multiply. Check by estimating. Let’s check by estimating.
Objective A
rounds to 2, rounds to 1, and 2 · 1 = 2.
The estimate is close to the exact value, so our answer is reasonable. 9

10. Example
An estimate for the measure of an adult’s wrist is of the waist size. If Jorge has a 34-inch waist, estimate the size of his wrist.
Objective A
Jorge’s wrist is about inches. 10