##
* *Reflection: Developing a Conceptual Understanding
Exploring Circumference - Section 2: Explore

This was a very cool activity! Students were excited about doing the actual measuring to generate their data. It wasn't difficult for them to determine that there was a connection between the two. Determining what that connection was took a little more time. One change I may make for the next time I do this activity would be two offer two different colors of yarn to each group. They can use one color for the circumference and one color for the diameter. That might make the connection easier to see.

*Do you see the connection?*

*Developing a Conceptual Understanding: Do you see the connection?*

# Exploring Circumference

Lesson 7 of 12

## Objective: SWBAT explore a relationship between diameter and circumference of a circle.

*35 minutes*

#### Explore

*30 min*

The exploration has several steps, including cutting and measuring. To ensure that students have enough time to finish the activity, we will not do a POD today.

To explore the relationship between the diameter and the circumference of a circle, students will measure the diameter and circumference of several circles. The sheet, Exploring CIrcumference, will be used to organize the data students generate. Students will receive between 2-4 circles and yarn and scissors. They will find the length of the circumference using the yarn for each circle. They will also measure the diameter of each circle and record the information on the data sheet. Once the data sheet is complete, students will review it to see if they recognize any patterns between the diameter and the circumference. They should complete the chart and other information on the data sheet. I want them to see that the circumference is “about” three times the diameter. After the recognition, we will work to develop a formula for finding the circumference. Do they recognize that pi is about 3? Are they familiar with pi? They will calculate the circumference for each other circles measured and discuss any observations and conclusions as a whole group.

#### Resources

*expand content*

#### Landing

*5 min*

To exit the class, I want students to sum up their thinking on circumference and how to find the circumference of any circle. How will they remember and apply a formula to find circumference? Do they have a “way” to remember or are they memorizing a formula and don’t yet understand, conceptually, what the formula represents? I wanted to leave the prompt a little vague to find out exactly what students think.

Tell me how to find the circumference of a circle. What does that mean?

*expand content*

##### Similar Lessons

Environment: Urban

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Environment: Urban

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- 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