Learn on PengiSaxon Math, Intermediate 4Chapter 7: Lessons 61–70, Investigation 7

Lesson 70: Word Problems About a Fraction of a Group

In this Grade 4 Saxon Math lesson (Intermediate 4, Chapter 7, Lesson 70), students learn how to solve word problems involving a fraction of a group by dividing the total number in a group by the fraction's denominator. Using rectangle diagrams as visual models, students practice finding unit fractions such as one-half, one-third, one-fourth, and one-fifth of whole numbers. The lesson builds understanding of how division connects to fractions in real-world contexts like counting sprouted seeds, students purchasing lunch, or points scored in a game.

Section 1

📘 Word Problems About a Fraction of a Group

New Concept

We can use fractions to name part of a whole, part of a group or number, and part of a distance.

What’s next

Next, you’ll draw diagrams and use division to find the fractional part of a group in word problems.

Section 2

Finding a fraction of a group

To find the number in a fractional part of a group, such as 12\frac{1}{2} or 13\frac{1}{3}, you simply divide the total amount by the denominator. The denominator, the bottom number of the fraction, tells you how many equal parts to split the whole group into. This calculation reveals the size of one of those equal parts.

To find 12\frac{1}{2} of 84 seeds, you calculate: 84÷2=4284 \div 2 = 42 seeds. If 13\frac{1}{3} of 27 students bought lunch, you find the number by calculating: 27÷3=927 \div 3 = 9 students. To determine 15\frac{1}{5} of 40, you perform the division: 40÷5=840 \div 5 = 8.

Imagine you have a big bag of candy to share with friends. To find your 13\frac{1}{3} share, just divide the total number of candies by 3. It’s the fastest and fairest way to split the treasure and find your portion!

Section 3

Drawing fraction diagrams

A powerful strategy for solving fraction problems is to draw a diagram. Begin by sketching a large rectangle to represent the total amount, or the whole group. Then, slice this rectangle into an equal number of parts based on the fraction's denominator. This visual map helps you see how the group is being divided, making it easier.

For 14\frac{1}{4} of 32 points, draw a rectangle with 4 rows. Each row represents 32÷4=832 \div 4 = 8 points. To find 13\frac{1}{3} of 60, draw a box, split it into 3 parts, and find the value of each part: 60÷3=2060 \div 3 = 20. Visualize 15\frac{1}{5} of 60 by drawing a rectangle with 5 sections where each is worth 60÷5=1260 \div 5 = 12.

Become a math artist! The rectangle is your canvas, representing the total. The denominator tells you how many equal strips to paint. This visual map makes understanding the division clear and simple, guiding you straight to the right answer.

Section 4

Fraction word problems

Word problems use fractions to describe a part of a total. Your first step is to read carefully and identify two key pieces of information: the total number in the group and the fraction that describes the part you need to find. Once you have these details, the solution is straightforward: simply divide the total by the denominator.

If 12\frac{1}{2} of 32 children were boys, find the number of boys by calculating: 32÷2=1632 \div 2 = 16 boys. When 13\frac{1}{3} of 24 coins are quarters, find the number of quarters with: 24÷3=824 \div 3 = 8 quarters. If one half of 74 seeds sprouted, you solve: 74÷2=3774 \div 2 = 37 sprouted seeds.

Don't let words fool you! In these story problems, just hunt for two clues: the total amount and the fraction. Once you spot them, you are one simple division step away from solving the entire mystery and finding the answer!

Book overview

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Chapter 7: Lessons 61–70, Investigation 7

  1. Lesson 1

    Lesson 61: Remaining Fraction, Two-Step Equations

  2. Lesson 2

    Lesson 62: Multiplying Three or More Factors, Exponents

  3. Lesson 3

    Lesson 63: Polygons

  4. Lesson 4

    Lesson 64: Division with Two-Digit Answers, Part 1

  5. Lesson 5

    Lesson 65: Division with Two-Digit Answers, Part 2

  6. Lesson 6

    Lesson 66: Similar and Congruent Figures

  7. Lesson 7

    Lesson 67: Multiplying by Multiples of 10

  8. Lesson 8

    Lesson 68: Division with Two-Digit Answers and a Remainder

  9. Lesson 9

    Lesson 69: Millimeters

  10. Lesson 10Current

    Lesson 70: Word Problems About a Fraction of a Group

  11. Lesson 11

    Investigation 7: Collecting Data with Surveys, Activity Class Survey

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

📘 Word Problems About a Fraction of a Group

New Concept

We can use fractions to name part of a whole, part of a group or number, and part of a distance.

What’s next

Next, you’ll draw diagrams and use division to find the fractional part of a group in word problems.

Section 2

Finding a fraction of a group

To find the number in a fractional part of a group, such as 12\frac{1}{2} or 13\frac{1}{3}, you simply divide the total amount by the denominator. The denominator, the bottom number of the fraction, tells you how many equal parts to split the whole group into. This calculation reveals the size of one of those equal parts.

To find 12\frac{1}{2} of 84 seeds, you calculate: 84÷2=4284 \div 2 = 42 seeds. If 13\frac{1}{3} of 27 students bought lunch, you find the number by calculating: 27÷3=927 \div 3 = 9 students. To determine 15\frac{1}{5} of 40, you perform the division: 40÷5=840 \div 5 = 8.

Imagine you have a big bag of candy to share with friends. To find your 13\frac{1}{3} share, just divide the total number of candies by 3. It’s the fastest and fairest way to split the treasure and find your portion!

Section 3

Drawing fraction diagrams

A powerful strategy for solving fraction problems is to draw a diagram. Begin by sketching a large rectangle to represent the total amount, or the whole group. Then, slice this rectangle into an equal number of parts based on the fraction's denominator. This visual map helps you see how the group is being divided, making it easier.

For 14\frac{1}{4} of 32 points, draw a rectangle with 4 rows. Each row represents 32÷4=832 \div 4 = 8 points. To find 13\frac{1}{3} of 60, draw a box, split it into 3 parts, and find the value of each part: 60÷3=2060 \div 3 = 20. Visualize 15\frac{1}{5} of 60 by drawing a rectangle with 5 sections where each is worth 60÷5=1260 \div 5 = 12.

Become a math artist! The rectangle is your canvas, representing the total. The denominator tells you how many equal strips to paint. This visual map makes understanding the division clear and simple, guiding you straight to the right answer.

Section 4

Fraction word problems

Word problems use fractions to describe a part of a total. Your first step is to read carefully and identify two key pieces of information: the total number in the group and the fraction that describes the part you need to find. Once you have these details, the solution is straightforward: simply divide the total by the denominator.

If 12\frac{1}{2} of 32 children were boys, find the number of boys by calculating: 32÷2=1632 \div 2 = 16 boys. When 13\frac{1}{3} of 24 coins are quarters, find the number of quarters with: 24÷3=824 \div 3 = 8 quarters. If one half of 74 seeds sprouted, you solve: 74÷2=3774 \div 2 = 37 sprouted seeds.

Don't let words fool you! In these story problems, just hunt for two clues: the total amount and the fraction. Once you spot them, you are one simple division step away from solving the entire mystery and finding the answer!

Book overview

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

Continue this chapter

Chapter 7: Lessons 61–70, Investigation 7

  1. Lesson 1

    Lesson 61: Remaining Fraction, Two-Step Equations

  2. Lesson 2

    Lesson 62: Multiplying Three or More Factors, Exponents

  3. Lesson 3

    Lesson 63: Polygons

  4. Lesson 4

    Lesson 64: Division with Two-Digit Answers, Part 1

  5. Lesson 5

    Lesson 65: Division with Two-Digit Answers, Part 2

  6. Lesson 6

    Lesson 66: Similar and Congruent Figures

  7. Lesson 7

    Lesson 67: Multiplying by Multiples of 10

  8. Lesson 8

    Lesson 68: Division with Two-Digit Answers and a Remainder

  9. Lesson 9

    Lesson 69: Millimeters

  10. Lesson 10Current

    Lesson 70: Word Problems About a Fraction of a Group

  11. Lesson 11

    Investigation 7: Collecting Data with Surveys, Activity Class Survey