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* *Reflection: Connection to Prior Knowledge
Circumference and Area - Section 1: Launch

Finding the circumference was a little challenging. Students substituted the diameter into the equation that they remembered and suddenly the area of the circle became the answer for the circumference. We worked on identifying the elements of the formula and exactly what the radius and diameter are and what they represent. I was excited that they had some knowledge of circles.

*Finding the circumference*

*Connection to Prior Knowledge: Finding the circumference*

# Circumference and Area

Lesson 4 of 12

## Objective: SWBAT calculate the circumference and area of circles

*40 minutes*

#### Launch

*5 min*

**POD**

As students enter the room, they will have a seat, take out their **Problem of the Day** (POD) sheet and begin to work on the question on the SMARTboard. The POD allows students to use **MP 3** continually based on the discussions we have about the problem each day.

**Learning Target**

The target for the day is also on the SMARTboard each day when students enter the room. The target for today’s lesson is for students to calculate the circumference and area of a circle.

To start class we will review the relationship between area and diameter and radius. Do students understand that the radius is half of the diameter? Do they understand the relationship between the circumference and pi? The POD will generate discussions where I can find the answers to these questions.

Find the radius and the circumference of a circle with a diameter of 10 cm.

#### Resources

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#### Explore

*30 min*

We will walk through a SMART notebook that builds upon the introduction to finding the circumference of a circle that we did in the previous class. Students will review the vocabulary then work through practice problems using radius and diameter to find the circumference. Students will also look at finding the area of circles. We will need to discuss what area means and how area is related to circumference. I would like students to discover a means to remember the formula for both area and circumference to avoid any application of the incorrect formula in a problem-solving situation.

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#### Landing

*5 min*

To wrap up the class, the exit ticket will be an opinion-gathering question for students to provide some feedback on their understanding. I want to know if they understand the difference between finding the area and finding the circumference. This formative information can help me decide if we need intervention on circumference or area or if we can move on because they understand.

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##### Similar Lessons

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*Resources(19)*

Environment: Urban

Environment: Suburban

- UNIT 1: Welcome to 7th Grade!
- UNIT 2: Number System
- UNIT 3: Geometric Measurement
- UNIT 4: Integers
- UNIT 5: Simplifying Expressions
- UNIT 6: Proportional Relationships
- UNIT 7: Percent Relationships
- UNIT 8: Equations and Inequalities
- UNIT 9: 2-D Measurements
- UNIT 10: 3-D Measurements
- UNIT 11: Angles
- UNIT 12: Probability

- LESSON 1: Circles Pre Assesment
- LESSON 2: Circles Vocabulary
- LESSON 3: Introduction to Circles
- LESSON 4: Circumference and Area
- LESSON 5: Eight Circles
- LESSON 6: More Eight Circles
- LESSON 7: Exploring Circumference
- LESSON 8: Write It Wednesday-Circles
- LESSON 9: Circles and Parallelograms
- LESSON 10: Circles Review
- LESSON 11: Circles Post Assessment
- LESSON 12: Area of Triangles