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9th Grade Math - Modeling through Geometry: Circumference of a Cup’s Roll

Clip 17/19: Modeling through Geometry: Lesson Part 4D


Molly McNinch asks her students to tape their posters up on the wall, and then engage in a “gallery walk,” encouraging them to “find one thing about one of the posters that you did not have on yours.” After Molly’s students examine their colleagues’ work, she asks them to identify strong elements in other posters, explaining the strategies that were used. Some students praise the labeling (e.g., a key) that other groups used. Other students identify the use of multiple shapes (not just cups, but cones, triangles). To close the lesson, Molly draws the whole group back together and asks them to return their materials and laptops to their places.

Teacher Commentary

I think that having a slightly larger group, focusing them to make a poster, focusing them to put all of their work in one place, allowed me to tell them to focus on the process that they were doing versus the solution. Groups of three are ideal here. Groups of four can be too big, and it is a difficult concept for two partners to focus on individually.

Instead of anticipating the misconceptions as, "Well, I think they're going to have trouble with the diameter and radius," which none of them had trouble with, it worked better to anticipate those needs as, "It might be best to put them in larger groups. It might be best to … change what they're producing just so that it's more familiar to them."