Learn on PengiIllustrative Mathematics, Grade 5Chapter 3: Multiplying and Dividing Fractions

Lesson 5: Apply Fraction Multiplication

In this Grade 5 lesson from Illustrative Mathematics Chapter 3, students apply fraction multiplication to solve real-world and mathematical problems involving multiplication of fractions and mixed numbers. Building on prior lessons in the Multiplying and Dividing Fractions unit, students practice setting up and computing fraction multiplication expressions in context. The lesson strengthens fluency with multiplying fractions by fractions and whole numbers through applied problem-solving tasks.

Section 1

Estimating Area with Fractions

Property

To estimate the area of a rectangle with fractional side lengths, round each dimension to the nearest compatible number (often a whole number) and then multiply.

Area \approx (rounded length) ×\times (rounded width)

Section 2

Finding Area with Mixed Number Side Lengths

Property

To find the area of a rectangle with mixed number side lengths, first convert the mixed numbers to improper fractions. Then, multiply the length and width.

A=l×wA = l \times w

Book overview

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Chapter 3: Multiplying and Dividing Fractions

  1. Lesson 1

    Lesson 1: Represent Unit Fraction Multiplication

  2. Lesson 2

    Lesson 2: Multiply Unit Fractions

  3. Lesson 3

    Lesson 3: Multiply Unit and Non-unit Fractions

  4. Lesson 4

    Lesson 4: Generalize Fraction Multiplication

  5. Lesson 5Current

    Lesson 5: Apply Fraction Multiplication

  6. Lesson 6

    Lesson 6: My Own Flag (Optional)

  7. Lesson 7

    Lesson 7: Concepts of Division (Optional)

  8. Lesson 8

    Lesson 8: Divide Unit Fractions by Whole Numbers

  9. Lesson 9

    Lesson 9: Divide Whole Numbers by Unit Fractions

  10. Lesson 10

    Lesson 10: Fraction Division Situations

  11. Lesson 11

    Lesson 11: Reason About Quotients

  12. Lesson 12

    Lesson 12: Represent Multiplication and Division Situations

  13. Lesson 13

    Lesson 13: Fraction Games

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Estimating Area with Fractions

Property

To estimate the area of a rectangle with fractional side lengths, round each dimension to the nearest compatible number (often a whole number) and then multiply.

Area \approx (rounded length) ×\times (rounded width)

Section 2

Finding Area with Mixed Number Side Lengths

Property

To find the area of a rectangle with mixed number side lengths, first convert the mixed numbers to improper fractions. Then, multiply the length and width.

A=l×wA = l \times w

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 3: Multiplying and Dividing Fractions

  1. Lesson 1

    Lesson 1: Represent Unit Fraction Multiplication

  2. Lesson 2

    Lesson 2: Multiply Unit Fractions

  3. Lesson 3

    Lesson 3: Multiply Unit and Non-unit Fractions

  4. Lesson 4

    Lesson 4: Generalize Fraction Multiplication

  5. Lesson 5Current

    Lesson 5: Apply Fraction Multiplication

  6. Lesson 6

    Lesson 6: My Own Flag (Optional)

  7. Lesson 7

    Lesson 7: Concepts of Division (Optional)

  8. Lesson 8

    Lesson 8: Divide Unit Fractions by Whole Numbers

  9. Lesson 9

    Lesson 9: Divide Whole Numbers by Unit Fractions

  10. Lesson 10

    Lesson 10: Fraction Division Situations

  11. Lesson 11

    Lesson 11: Reason About Quotients

  12. Lesson 12

    Lesson 12: Represent Multiplication and Division Situations

  13. Lesson 13

    Lesson 13: Fraction Games