### Lesson plan

# Fraction of a Whole

#### Learning Objectives

Students will be able to use bar models and multiplication to find a fraction of a whole number.

#### Introduction

*(5 minutes)*

- Hook students with a scenario: "My favorite TV show is 27 minutes long. Usually I watch it on Friday evenings, but last Friday I fell asleep after watching only ⅓ of the show. I want to finish watching it, but I need to figure out how many minutes I’ve already watched so I can start in the right place."
- Tell students that in order to figure out how many minutes were watched, we will have to find one-third of 27. So today, we are going to learn how to find fractions of a whole number.

#### Explicit Instruction/Teacher modeling

*(10 minutes)*

- Restate scenario ("I watched ⅓ of a 27 minute show. How many minutes did I watch?").
- Write the problem on the board (
**⅓ of 27**). - Draw a bar and label it "27." Explain, "The whole TV show is 27 minutes, so this bar will represent the total length of the show."
- Beneath the first bar, draw a bar that is the same length and divide it into thirds. Explain, "I only watched one third of the show before falling asleep."
- Lightly shade one part, or ⅓, and tell students, this shaded part represents the part of the show you watched.
- Point out that there are three equal parts in the bottom bar. Remind students that the total length is 27, so in order to find out what each of the ⅓ parts is, we will have to divide 27 into three equal parts (
**27 ÷ 3**). - Call on a student to give the answer to
**27 ÷ 3**, and write the answer, 9, in each of the three parts of the bottom bar. - Remind students that the shaded ⅓ represents the part you watched, and explain: with this bar model, we can see that ⅓ of 27 is 9. So, "I watched 9 minutes of my favorite TV show."
- Point to the unshaded portion of the bottom bar and ask students how many minutes are left in the show. Give students time to discuss with a partner, then call on a student to share (i.e.,
**9 + 9 = 18**; 18 minutes are left in the show). - Explain that a
**Bar model**Is one way to find a fraction of a whole. It helps us visualize the whole number and it also shows the whole divided into equal parts.

#### Guided practise

*(15 minutes)*

- Guide students through another example of a bar model, like ⅚ of 12.
- After drawing and shading the bar model, write a repeated addition sentence (e.g.,
**2 + 2 + 2 + 2 + 2 = 10**) and explain that since ⅙ of 12 is 2, and ⅚ are shaded, we need to add five parts, or sixths, to find the answer. - Tell students that another way to find a fraction of a whole number is to multiply.
- Write ⅖ of 20 on the board.
- Explain, "When we multiply a fraction by a whole number, we can just multiply it by the numerator. The denominator remains the same (write
**20 x 2/5 = 40/5**)." - Tell students that this is because a whole number is equal to itself over one (
**20 = 20/1**). - Point out that 40/5 is an improper fraction, and remind students that, in order to simplify the fraction, we must divide the numerator (40) by the denominator (5). Write
**40/5 = 8**On the board. - Write
**⅖ of 20 = 8**And discuss the answer. - Hand out the Multiplication: Fraction of a Whole worksheet and review the example problem.
- Instruct students to complete the first problem with a partner.

#### Independent working time

*(10 minutes)*

- Have students complete the remaining problems on both worksheets independently.
- Circulate as students work and offer support as needed.
- Go over the worksheets as a class.

#### Differentiation

**Support:**

- Teach repeated addition as a precursor to multiplication.
- Provide completed bar models and have students write a repeated addition sentence to go with the models.

**Enrichment:**

- Have students apply the strategies learned in the lesson to solve two-step word problems.

#### Assessment

*(5 minutes)*

- Hand out a blank sticky note to each student.
- Write a problem on the board, like
**⅗ of 10**. Instruct students to solve this on their sticky note using the method of their choice. - Collect the sticky note as an exit ticket and check for understanding.

#### Review and closing

*(10 minutes)*

- Show students the "Multiply Fractions with Whole Numbers Song" video.