Created on: June 23, 2009

Website Address: https://library.curriki.org/oer/Lesson--9-Comparing-Fractions-II

IN COLLECTION

Prior to beginning the lesson: (1) Photocopy the **Problem of the Day** onto transparency paper for the overhead projector.

**Group Size:** Whole class

**Learning Objectives:**

Students will be able to:

- Compare fractions and explain why fractions are smaller or bigger than one another.
- Understand that bigger fractions have smaller denominators.
- Understand that two different fractions can equal one another.

**Problem of the Day** (see attachment), “Fractions Around Us” Chart (from Lesson #2), paper plates (3 per student), rulers, red crayons, blue crayons, green crayons, overhead projector

**Procedures:**

Lesson Introduction: Display **Problem of the Day** on the overhead projector. Ask students: *What strategy should we use to solve this problem?* Guide them towards drawing a picture. Solve the problem together as a class. Students can copy problem and solution into math notebooks.

- Review the chart “Fractions Around Us” from Lesson #2. If students have any other ideas, add them to the list.
- Tell students:
*We all know that one place we see fractions is pizza. Today, we are going to practice fractions with pizza.* - Distribute paper plates, crayons, and rulers to students.
- Direct students to mark the center of a paper plate with a dot and then to use a ruler to draw a line across the plate. Ask students:
*How should we label the parts of the plate?*Instruct student to label each part with “1/2” and to color in one part with a red crayon. - Direct students to mark the center of the second paper plate with a dot and to use a ruler to divide the plate into fourths. Ask students:
*How should we label the parts of the plate?*Instruct students to label each part with “1/4” and to color in one part with a red crayon. - Direct students to mark the center of the third paper plate with a dot and to use a ruler to divide the plate into eighths. Ask students:
*How should we label the parts of the plate?*Instruct students to label each part with “1/8” and to color in one part with a red crayon. - Have students look at all three plates. Ask them:
*Which piece of pizza is the biggest? Which is the smallest? What happens to the size of the pizza slice as the denominator gets bigger?* - Tell students:
*Look at your pizza that is divided into fourths. Take a green crayon and color in one-fourth green.*Once students have done that, ask them:*Look at your fourths pizza again. It looks like two-fourths is the same as what other piece of pizza?*Make sure students understand that two-fourths is the same as one-half. Write “2/4 = 1/2” on the board. - Tell students:
*Look at your pizza that is divided into eighths. Take a green crayon and color in one-eighth green.*Once students have done that, ask them:*Look at your eighths pizza again. It looks like two-eighths is the same as what other piece of pizza?*Make sure students understand that two-eighths is the same as one-fourth. Write “2/8 = 1/4” on the board. - Tell students:
*Take a look at one-half and one fourth. What can we say about those two fractions?*Guide students towards the answer, and write “1/2 > 1/4” on the board. Ask students:*What do you notice about the size of the fraction as the denominator gets bigger?* - Continue asking questions, making comparisons, and writing them on the board until students understand.
- Challenge students to come up with their own comparisons.

**Assessment:**

Teacher should monitor student participation and independent work to ensure all students understand the concept.

**Benchmark or Standards:**

National Council of Teachers of Mathematics (NCTM) Number and Operations Standard:

- Develop a sense of whole numbers and represent and use them in flexible ways, including relating, composing, and decomposing numbers.
- Understand and represent commonly used fractions, such as 1/4, 1/3, and 1/2.

- Pose questions and gather data about themselves and their surroundings.

- Build new mathematical knowledge through problem solving.
- Recognize and apply mathematics in contexts outside of mathematics.

Lesson9Resources.FunwithFractions.pdf |