## Reflection: Checks for Understanding Finding the Perimeter of Odd-Shaped Dog Pens - Section 3: Student Practice

I was so impressed with students during student practice time! They were able to work at their own levels and at different paces.

During this time, I tried to act as a coach, guiding and questioning. Below are several examples of teachable moments!

Revising Strategies: This student realized that decomposing the odd-shaped dog pen and multiplying the sides didn't help him find the perimeter. I gave him a red pen to revise his work.

Making More Precise: Students make their work more precise by distinguishing measurements.

Adding vs. Subtracting: Students realized they needed to subtract instead of add. At first, they struggled with figuring out which numbers to subtract.

Make it Simpler: Two students use what they know to find missing dimensions.

Collaborative Learning: This is one of my favorite moments in this lesson! Through discussion, students worked together to discover why they got different answers.

Truly Beginning to Understand: Two partners figure out how to explain the length of a side beyond "having a gut feeling."

Which Dimensions Should be Included?: These students try to figure out which dimensions should be included.

Checks for Understanding: Teacher Observations

# Finding the Perimeter of Odd-Shaped Dog Pens

Unit 14: Area & Perimeter
Lesson 18 of 19

## Big Idea: Students will discover how to use known side dimensions to determine unknown side dimensions when finding the perimeter of odd-shaped dog pens.

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4 teachers like this lesson
Standards:
100 minutes

### Kara Nelson

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