Multiplying Fractions and 3 9 Mixed Numbers Warm

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

Multiplying Fractions and 3 -9 Mixed Numbers Warm Up 1 What is 2 of each of the following? 1. 24 12 3. 30 15 2. 16 4. 28 8 14

Multiplying Fractions and 3 -9 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.

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

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

Multiplying Fractions and 3 -9 Mixed Numbers Additional Example 1 A: Multiplying Fractions Multiply. Write the answer in simplest form. – 12 · 3 4 3 = – 12 · 3 Write – 12 as a fraction. – 12 · 4 1 4 3 12 · 3 Simplify. =– 1 · 41 = – 9 Multiply numerators. 1 Multiply denominators. Helpful Hint The product of two positive proper fractions is less than either fraction.

Multiplying Fractions and 3 -9 Mixed Numbers Additional Example 1 B: Multiplying Fractions Multiply. Write the answer in simplest form. 1 · 3 3 8 1 · 3 = 1 · 3 3 8 13· 8 = 1 8 1 Simplify. Multiply numerators. Multiply denominators.

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

Multiplying Fractions and 3 -9 Mixed Numbers Check It Out: Example 1 A Multiply. Write the answer in simplest form. – 16 · 1 4 1 = – 16 · 1 Write – 16 as a fraction. – 16 · 4 1 4 4 16 · 1 Simplify. =– 1 · 41 = – 4 Multiply numerators. 1 Multiply denominators.

Multiplying Fractions and 3 -9 Mixed Numbers Check It Out: Example 1 B Multiply. Write the answer in simplest form. 1 · 6 6 9 1 · 6 = 1 · 6 6 9 16· 9 = 1 9 1 Simplify. Multiply numerators. Multiply denominators.

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

Multiplying Fractions and 3 -9 Mixed Numbers Additional Example 2 A: Multiplying Mixed Numbers Multiply. Write the answer in simplest form. 2 · 12 5 3 2 · 12 = 2· 5 5 3 3 5 = 2· 5 5 3 1 =2 3 Write the mixed number as an improper fraction. 1 Simplify. Multiply numerators. Multiply denominators.

Multiplying Fractions and 3 -9 Mixed Numbers Additional Example 2 B: Multiplying Mixed Numbers Multiply. Write the answer in simplest form. · 21 41 7 5 41 · 2 1 = 21 · 15 Write the mixed numbers as 5 7 improper fractions. 3 3 21 · 15 Simplify. = 5 7 1 1 or 9 = 9 1 Multiply numerators. Multiply denominators.

Multiplying Fractions and 3 -9 Mixed Numbers Additional Example 2 C: Multiplying Mixed Numbers Multiply. Write the answer in simplest form. 2 63 · 2 45 6 2 · 4 2 = 20 · 22 3 5 4 = 20 · 22 3 51 = 88 or 29 1 3 3 Write the mixed numbers as improper fractions. Simplify. Multiply numerators. Multiply denominators.

Multiplying Fractions and 3 -9 Mixed Numbers Check It Out: Example 2 A Multiply. Write the answer in simplest form. 3 · 21 5 3 3 · 21 = 3· 7 5 3 3 5 Write the mixed number as an improper fraction. 13 7 = · Simplify. 5 31 = 7 or 12 Multiply numerators. 5 5 Multiply denominators.

Multiplying Fractions and 3 -9 Mixed Numbers Check It Out: Example 2 B Multiply. Write the answer in simplest form. · 11 33 3 6 33 · 1 1 = 21 · 6 3 6 7 21 · = 6 3 4 3 2 4 3 1 Write the mixed numbers as improper fractions. Simplify. 2 Multiply numerators. 14 or 4 = 3 3 Multiply denominators.

Multiplying Fractions and 3 -9 Mixed Numbers Check It Out: Example 2 C Multiply. Write the answer in simplest form. 1 36 · 1 13 3 1 · 1 1 = 19 · 4 6 3 2 19 4 = · 6 3 3 = 38 or 4 2 9 9 Write the mixed numbers as improper fractions. Simplify. Multiply numerators. Multiply denominators.

Multiplying Fractions and 3 -9 Mixed Numbers Additional Example 3: Transportation Application In 2001, the car toll on the George Washington Bridge was $6. 00. In 1995 the toll was 2 of that 3 toll. What was the toll in 1995? 6 · 2 = 2+ 2 + 2 + 2 3 3 3 3 = 12 3 1 1 3 3 + 1 1 3 3 + 1 1 3 3 1 1 1 3 3 3 4 = 1 Simplify. = $4. 00 Divide 4 by 1 to write the fraction as a decimal. 1 1 The George Washington Bridge toll for a car was $4. 00 in 1995.

Multiplying Fractions and 3 -9 Mixed Numbers Check It Out: Example 3 In 2002, the fee to park in a parking garage was 3 $4. In 2000 the fee was 4 of the fee in 2002. What was the fee in 2000? 4· 3 =3 + 3 +3 4 4 4 = 12 4 111 444 + 111 444 111111 444444 3 = 1 Simplify. = $3. 00 Divide 3 by 1 to write the fraction as a decimal. 1 1 1 The fee to park in the parking garage was $3. 00 in 2000.

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

Multiplying Fractions and 3 -9 Mixed Numbers Lesson Quiz: Part I Multiply. Write each answer in simplest form. 1. 1 · 5 8 6 5 48 2. 5 5 · 1 6 2 35 or 2 11 12 12 3. 5 1 · 1 2 10 3 17 or 8 1 2 2 4. 3 · 4 2 16 3 7 8

Multiplying Fractions and 3 -9 Mixed Numbers Lesson Quiz: Part II Multiply. Write the answer in simplest form. 5. A recipe for clam chowder calls for 2 41 pounds of butter. If you prepare one-half of the recipe, how much butter do you need? 1 1 pounds 8

Multiplying Fractions and 3 -9 Mixed Numbers Lesson Quiz for Student Response Systems 1. Multiply. Write your answer in simplest form. 1· 4 9 5 4 A. C. 45 1 9 1 B. D. 6 1 10

Multiplying Fractions and 3 -9 Mixed Numbers Lesson Quiz for Student Response Systems 2. Multiply. Write your answer in simplest form. 44 · 1 5 3 8 or 1 3 5 5 A. 17 or 5 2 3 3 C. B. 16 or 3 1 5 5 D. 4 5

Multiplying Fractions and 3 -9 Mixed Numbers Lesson Quiz for Student Response Systems 3. Multiply. Write your answer in simplest form. 6 1 · 12 4 5 A. 35 or 8 3 4 4 C. 26 or 5 1 5 5 B. 27 or 6 3 4 4 D. 24 or 4 4 5 4

Multiplying Fractions and 3 -9 Mixed Numbers Lesson Quiz for Student Response Systems 4. Multiply. Write your answer in simplest form. 5 · 34 18 5 A. 8 9 C. 19 or 1 1 18 18 B. 17 18 D. 1 1 9

Multiplying Fractions and 3 -9 Mixed Numbers Lesson Quiz for Student Response Systems 3 5. To prepare one bowl of salad, 3 pounds 4 of vegetables are required. How many pounds of vegetables are required to prepare one-third bowl of salad? A. 1 1 lb C. 1 3 lb 4 4 B. 1 1 lb 2 D. 13 lb 5