Multiply Write in simplest form 1 2 3

Multiply. Write in simplest form. 1. 2. 3. 4. 5. Half the students in an elementary school live less than 2 miles from the building. Of these, ride the bus to school. What fraction of students live less than 2 miles from the building and ride the bus to school? Course 1, Lesson 4 -3

ANSWERS 1. 2. 3. 4. 5. Course 1, Lesson 4 -3

The Number System WHAT does it mean to multiply and divide fractions? Course 1, Lesson 4 -3

The Number System • Preparation for 6. NS. 1 Interpret and compute quotients of fractions, and solve word problems involving division of fractions by fractions, e. g. , by using visual fraction models and equations to represent the problem. Mathematical Practices 1 Make sense of problems and persevere in solving them. 3 Construct viable arguments and critique the reasoning of others. 4 Model with mathematics. 5 Use appropriate tools strategically. Course 1, Lesson 4 -3 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.

The Number System • To multiply fraction and a mixed number • To multiply mixed numbers Course 1, Lesson 4 -3

Step-by-Step Example 1. 1 Estimate Use compatible numbers. as × 2=1 2 Write . 3 Multiply. 4 Simplify. Compare to the estimate. Need Another Example?

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Step-by-Step Example 2. 1 2 3 1 Estimate 6 2 3 11 Write as an improper fraction. 2 11 × 1 Multiply. 2× 3 4 5 11 5 6 6 Simplify. Check for Reasonableness Need Another Example?

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Step-by-Step Example 3. Write 1 5 5 4 1 2 as . Write as . Divide 15 and 3 by their GCF, 3. Then divide 10 and 8 by their GCF, 2. 3 Multiply the numerators and multiply the denominators. 4 Simplify. Need Another Example?

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Step-by-Step Example 4. The Hoover Dam contains 4 million cubic yards of concrete. The Grand Coulee Dam, in Washington state, contains 2 times as much concrete. How much concrete does it contain? 1 Estimate 4 × 3 = 12 Write the mixed numbers as improper fractions. 2 3 4 1 1 3 Divide 9 and 3 by their GCF, 3. Then divide 8 and 2 by their GCF, 2. 4 Multiply the numerators and multiply the denominators. 5 Simplify. 6 There are 12 million cubic yards of concrete in the Grand Coulee Dam. 7 Check for Reasonableness 12 = 12 Need Another Example?

Need Another Example? Adriana is making banana bread for a class bake sale. The recipe calls for 1 cups of brown sugar. She is making 5 times the recipe. How much brown sugar does Adriana need? Answer

Step-by-Step Example 5. Mr. Conrad’s pecan pie recipe calls for 1 cups of pecans. He plans to make 8 pies for his family reunion. How many cups of pecans will Mr. Conrad need? 1 Estimate 2 × 8 = 16 2 2 Write the mixed number as an improper fraction. Write the whole number as a fraction with a denominator of 1. Divide 8 and 4 by their GCF, 4. 3 1 4 Multiply the numerators and multiply the denominators. 5 Simplify. 6 Check for Reasonableness 7 Mr. Conrad will need 14 cups of pecans. 14 ≈ 16 Need Another Example?

Need Another Example? A recipe for chocolate chip cookies calls for 1 cups of flour. Megan needs to make 6 batches of cookies for a cookie exchange. How many cups of flour will she need? Answer

The Number System How did what you learned today help you answer the WHAT does it mean to multiply and divide fractions? Course 1, Lesson 4 -4

The Number System How did what you learned today help you answer the WHAT does it mean to multiply and divide fractions? Sample answer: • To find the portion of more than one set • To find more than one portion of more than one set Course 1, Lesson 4 -4

Ratios and Proportional The Number Relationships System Compare multiplying mixed numbers to multiplying fractions. Then write about how the previous lesson helped you to understand the concepts introduced in this lesson. Course 1, Lesson 4 -4