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* *Reflection: Adjustments to Practice
Circumference from Area / Area from Circumference - Section 1: Teacher Model

In the reflection from the previous lesson I suggested setting up the lesson so that students discover how to find the radius and diameter when given the circumference or area of a circle. Using that approach allowed me to skip most of that lesson and combine it with this lesson. This saved me a day in my unit which I could use later for re-teaching or extending a concept!

I started this warmup with a short refresh on finding the radius and diameter. I then allowed students to try the examples on their own. I only had to help a few students find the radius and diameter. Most then saw that once they find the radius from a given circumference they can then use that radius to find the area.

*Suggested Changes*

*Adjustments to Practice: Suggested Changes*

# Circumference from Area / Area from Circumference

Lesson 11 of 37

## Objective: SWBAT determine the circumference of a circle given its area and vice versa

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#### Guided Practice

*10 min*

The students will work through the guided practice problems using their notes and partners as a resource. These problems mirror the example problems, but also include problems where 3.14 is used for PI. I will monitor student work looking for common problems to bring to the attention to the entire class.

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#### Independent Practice

*20 min*

Students now work independently on the next set of problems. These mirror the work just done, so students who are having difficulty should have several models to refer to. If I am asked a question, I will first point students to those models from the examples or guided practice.

The extension problem is included to provide another “real-world” area and circumference task. Part I requires students to explain their thinking (**MP3**) . It requires an attention to precision (**MP6**) as students must realize that the radius is not the same at all points on the walkway.

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#### Exit Ticket

*5 min*

Students take an exit ticket. The first two problems are multiple choice to catch common errors through the distracter items. Problems 3 and 4 are open ended.

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##### Similar Lessons

Environment: Urban

Environment: Suburban

###### Old and New Knowledge of Circles

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Environment: Urban

- LESSON 1: Explore Perimeter and Area of Composite Shapes
- LESSON 2: Perimeter of Irregular Rectilinear Shapes
- LESSON 3: Area of Composite Shapes Using a Grid
- LESSON 4: Area of Composite Shapes
- LESSON 5: Area of Regions Formed by Inscribed Shapes
- LESSON 6: CORNERSTONE:Circle Ratios: Diameter to Radius; Circumference to Diameter
- LESSON 7: CORNERSTONE: Circumference Formula
- LESSON 8: Area of a Circle
- LESSON 9: Circumference & Area Fluency Practice
- LESSON 10: Finding the Radius From a Given Circumference or Area
- LESSON 11: Circumference from Area / Area from Circumference
- LESSON 12: Circle Designs: Finding the Area and Perimeter of Shapes Composed of Arcs and Line Segments
- LESSON 13: Assessment_Area and Perimeter (Circumference) of Composite Shapes and Circles
- LESSON 14: Drawing Prisms & Pyramids
- LESSON 15: Describe Prisms and Pyramids Using Algebra
- LESSON 16: Using Nets to Find the Surface Area of Prisms
- LESSON 17: Using a Formula to Find the Surface Area of Prisms
- LESSON 18: Finding the surface area of triangular prisms using a net
- LESSON 19: Finding the Surface Area of a Triangular Prism Using A Formula
- LESSON 20: Discovering the Formula for the Surface Area of A Cylinder
- LESSON 21: Finding the Surface Area of Cylinders Using a Formula
- LESSON 22: Practice Day: Surface Area of Prisms & Cylinders
- LESSON 23: Surface Area of Prisms and Cylinders Assessment
- LESSON 24: Finding the Surface Area of Pyramids Using Nets
- LESSON 25: Finding the Surface Area of Pyramids Using a Formula
- LESSON 26: Surface Area of Composite Shapes
- LESSON 27: Surface Area of Composite Shapes With Holes
- LESSON 28: Surface Area Assessment
- LESSON 29: 3-D Models from 2-D Views
- LESSON 30: Exploring Volume and Surface Area with Unifix Cubes
- LESSON 31: Explore Volume of Rectangular Prisms
- LESSON 32: Find the Volume of Prisms Using a Formula
- LESSON 33: Volume Of Cylinders Using a Formula
- LESSON 34: Volume of Composite Shapes
- LESSON 35: Volume and Surface Area - Accelerated Math Fluency Day
- LESSON 36: Volume of Pyramids
- LESSON 37: Surface Area and Volume Final Assessment