3-9 Multiplying Fractions and Mixed Numbers Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day Lesson Quizzes Lesson Quizzes Objective: students multiply fractions and mixed numbers

3-9 Multiplying Fractions and Mixed Numbers Warm Up What is of each of the following?

3-9 Multiplying Fractions and Mixed Numbers Problem of the Day At midnight Caitlin heard a forecaster say that it would be cloudy for exactly 72 hours and then would be sunny. Caitlin knew the forecaster was wrong. Explain. There are 24 hours in a day, so 72 hours equals 3 days. In 3 days it would be midnight again, not sunny.

3-9 Multiplying Fractions and Mixed Numbers Learn to multiply fractions and mixed numbers.

3-9 Multiplying Fractions and Mixed Numbers To multiply fractions, multiply the numerators to find the product’s numerator. Then multiply the denominators to find the product’s denominator.

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 1A: Multiplying Fractions –12 · = – 12 1 · 3 4 Write –12 as a fraction. = – 12 · 3 1 · Simplify. 9 1 = – = –9 Multiply numerators. Multiply denominators. The product of two positive proper fractions is less than either fraction. Helpful Hint

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 1B: Multiplying Fractions · 8 = Simplify. Multiply numerators. Multiply denominators = · · 3 8 ·

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 1C: Multiplying Fractions · 4 The signs are different, so the answer will be negative. Multiply numerators. Multiply denominators – · – = 3 5 · 1 4 · – = 3 20 –

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out: Example 1A –16 · = – 16 1 · 1 4 Write –16 as a fraction. = – 16 · 1 1 · Simplify. 4 1 = – = –4 Multiply numerators. Multiply denominators.

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out: Example 1B · 9 = Simplify. Multiply numerators. Multiply denominators = · · 6 9 ·

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out: Example 1C · 8 The signs are different, so the answer will be negative. Multiply numerators. Multiply denominators – 1 8 · 3 7 – = 3 7 · 1 8 · – = 3 56 –

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 2A: Multiplying Mixed Numbers Write the mixed number as an improper fraction. Simplify. Multiply numerators. Multiply denominators · = 2 5 · 5 3 = 2 5 · · = 2 3

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 2B: Multiplying Mixed Numbers Write the mixed numbers as improper fractions. Simplify · · 1 7 = 21 5 · 15 7 = 5 · = 9 1 or 9 Multiply numerators. Multiply denominators. 2

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 2C: Multiplying Mixed Numbers Multiply numerators. Multiply denominators. 2 3 · · = 20 3 · · 22 5 = 4 1 Write the mixed numbers as improper fractions. Simplify. 3 = 88 or

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out: Example 2A Write the mixed number as an improper fraction. Simplify. Multiply numerators. Multiply denominators · = 3 5 · 7 3 = 3 5 · · = or

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out: Example 2B Write the mixed numbers as improper fractions. Simplify · · 1 3 = 21 6 · 4 3 = 6 · Multiply numerators. Multiply denominators. 1 = 14 3 or 4 2 3

3-9 Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Multiply numerators. Multiply denominators. 1 6 · · = 19 6 · · 4 3 = 3 2 Write the mixed numbers as improper fractions. Simplify. 9 = 38 or Check It Out: Example 2C

3-9 Multiplying Fractions and Mixed Numbers In 2001, the car toll on the George Washington Bridge was $6.00. In 1995 the toll was Additional Example 3: Transportation Application 2 3 of that toll. What was the toll in 1995? · = = 12 3 = 4 1 Simplify. = $4.00 Divide 4 by 1 to write the fraction as a decimal. The George Washington Bridge toll for a car was $4.00 in

3-9 Multiplying Fractions and Mixed Numbers In 2002, the fee to park in a parking garage was $4. In 2000 the fee was of the fee in What was the fee in 2000? Check It Out: Example · = = 12 4 = 3 1 Simplify. = $3.00 Divide 3 by 1 to write the fraction as a decimal. The fee to park in the parking garage was $3.00 in

3-9 Multiplying Fractions and Mixed Numbers Standard Lesson Quiz Lesson Quizzes Lesson Quiz for Student Response Systems

3-9 Multiplying Fractions and Mixed Numbers Lesson Quiz: Part I Multiply. Write each answer in simplest form · · · · or or

3-9 Multiplying Fractions and Mixed Numbers Lesson Quiz: Part II Multiply. Write the answer in simplest form. 5.A recipe for clam chowder calls for pounds of butter. If you prepare one-half of the recipe, how much butter do you need? pounds

3-9 Multiplying Fractions and Mixed Numbers 1. Multiply. Write your answer in simplest form. · A. C. B. D. Lesson Quiz for Student Response Systems

3-9 Multiplying Fractions and Mixed Numbers 2. Multiply. Write your answer in simplest form. 4 · A. or 5C. or 1 B. or 3 D. Lesson Quiz for Student Response Systems

3-9 Multiplying Fractions and Mixed Numbers 3. Multiply. Write your answer in simplest form. 6 · 1 A. or 8C. or 5 B. or 6 D. or 4 Lesson Quiz for Student Response Systems

3-9 Multiplying Fractions and Mixed Numbers 4. Multiply. Write your answer in simplest form. · 3 A. C. or 1 B. D. 1 Lesson Quiz for Student Response Systems

3-9 Multiplying Fractions and Mixed Numbers 5. To prepare one bowl of salad, 3 pounds of vegetables are required. How many pounds of vegetables are required to prepare one-third bowl of salad? A. 1 lbC. 1 lb B. 1 lbD. 1 lb Lesson Quiz for Student Response Systems