## Reflection: Checks for Understanding Circumference & Area Fluency Practice - Section 2: Whiteboard Practice

After a few problems of each type, my students were able to find the circumference and area of any circle - as long as the radius and diameter were presented as whole numbers.  Fractions really caused problems.

When I gave a diameter like 8 1/2 and asked students to find the area many  were stumped.  I had to ask students to tell me what measure was needed to find the area.  They knew they needed the radius but the fraction made it difficult for them.  I asked them what they would do to find the area if the diameter was 10 units.  They responded, as if I were stupid, that you would divide the diameter by 2.  So then I asked, what should we do to find the radius when the diameter is 8 1/2.  I had to go through this a few times.

It's a good thing we spent so much time on this because the accelerated math practice in the next part of the lesson is full of fractions and decimals.

Radii and Diameters - Fractions, Mixed Numbers, and Decimals
Checks for Understanding: Radii and Diameters - Fractions, Mixed Numbers, and Decimals

# Circumference & Area Fluency Practice

Unit 6: Geometry
Lesson 9 of 37

## Big Idea: Whiteboard practice!

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2 teachers like this lesson
Standards:
Subject(s):
Math, circumference (Determining Measurements), Geometry, 7th grade, circles, area of circle
55 minutes

### Grant Harris

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