CER Instructional Strategy

Claim Evidence Reasoning Strategy in Math

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Geometry Example

https://learn.k20center.ou.edu/lesson/1411

Slice of Pi: Area and Circumference of a Circle

What’s the Ratio?

Create a CER (Claim, Evidence, Reading) statement about the situation.

Write a 1-2 sentence claim based on the statement: “No matter the size of a circle, its ratio is the same.”

Show your evidence and work from the measurements at each station.

Write a 3-4 sentence conclusion, providing explanations for why the data you chose counts as evidence and supports your claim.

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DIRECTIONS

1. Write the Claim in the Circles Ratio CER handout.
2. Use the string and ruler to measure each of the three circles. You may use your own or use the examples on slide 6. Write this on the Evidence section of your CER handout.
3. Write your Reasoning on the appropriate section of your CER handout.