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

Lesson 10: Fraction Division Situations

In this Grade 5 lesson from Illustrative Mathematics Chapter 3, students apply their understanding of dividing a whole number by a unit fraction and a unit fraction by a whole number to write and solve real-world word problems. Using a card sort activity, students match situations to expressions such as 5 ÷ 1/4 and 1/4 ÷ 5, interpreting what each equation means in context. The lesson builds fluency with fraction division and addresses standards 5.NF.B.7 and 5.NF.B.7.c.

Section 1

Applying Partitive Division: Fraction ÷ Whole Number

Property

Partitive division with a fraction dividend and whole number divisor, ab÷c\frac{a}{b} \div c, answers the question: "If an amount ab\frac{a}{b} is split into cc equal groups, what is the size of one group?"

Examples

Section 2

Applying Quotative Division: Whole Number ÷ Unit Fraction

Property

Quotative division, or measurement division, answers the question "how many groups of a certain size are in a given amount?" When dividing a whole number by a unit fraction, we are finding how many fractional pieces fit into the whole.

a÷1b=a×ba \div \frac{1}{b} = a \times b

Examples

  • How many 14\frac{1}{4}-cup servings are in 3 cups of sugar?
3÷14=3×4=12 servings3 \div \frac{1}{4} = 3 \times 4 = 12 \text{ servings}
  • A baker has 5 pounds of flour. How many 12\frac{1}{2}-pound bags can he make?
5÷12=5×2=10 bags5 \div \frac{1}{2} = 5 \times 2 = 10 \text{ bags}

Explanation

This skill applies division to real-world scenarios where you need to find out how many smaller, fractional units can be made from a larger whole amount. This is known as quotative or measurement division. For example, if you are dividing 2 pies into slices that are 16\frac{1}{6} of a pie each, you are asking how many groups of 16\frac{1}{6} are in 2. Dividing a whole number by a unit fraction results in a larger whole number, as you are finding the total number of fractional parts within the wholes.

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 5

    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 10Current

    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

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Section 1

Applying Partitive Division: Fraction ÷ Whole Number

Property

Partitive division with a fraction dividend and whole number divisor, ab÷c\frac{a}{b} \div c, answers the question: "If an amount ab\frac{a}{b} is split into cc equal groups, what is the size of one group?"

Examples

Section 2

Applying Quotative Division: Whole Number ÷ Unit Fraction

Property

Quotative division, or measurement division, answers the question "how many groups of a certain size are in a given amount?" When dividing a whole number by a unit fraction, we are finding how many fractional pieces fit into the whole.

a÷1b=a×ba \div \frac{1}{b} = a \times b

Examples

  • How many 14\frac{1}{4}-cup servings are in 3 cups of sugar?
3÷14=3×4=12 servings3 \div \frac{1}{4} = 3 \times 4 = 12 \text{ servings}
  • A baker has 5 pounds of flour. How many 12\frac{1}{2}-pound bags can he make?
5÷12=5×2=10 bags5 \div \frac{1}{2} = 5 \times 2 = 10 \text{ bags}

Explanation

This skill applies division to real-world scenarios where you need to find out how many smaller, fractional units can be made from a larger whole amount. This is known as quotative or measurement division. For example, if you are dividing 2 pies into slices that are 16\frac{1}{6} of a pie each, you are asking how many groups of 16\frac{1}{6} are in 2. Dividing a whole number by a unit fraction results in a larger whole number, as you are finding the total number of fractional parts within the wholes.

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 5

    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 10Current

    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