Lesson

# Clip 11/13: Calculating Volume of Rectangular Prisms Lesson Part 2D

## Overview

As her 5th-grade students finish drawing the strategies that they used in each act of the Three-Act Task, Mallory circulates around the groups. Students use the printed images of the third act—the disassembled box—annotating and drawing to indicate how their estimates were connected to what they observed. She comments, “One of the things I’m talking to the other group about is that volume is not just the formula. Okay? We’re used to plugging in a formula, length times width times height. But what’s harder is when you see the front of this box, what’s behind it?... How can we visually draw a picture to show that we think there’s 12 layers of 18?”

## Teacher Commentary

I was surprised that a lot of the students didn't choose to interact with the picture or visual that they were given. They just put an estimate down on the paper based on what they just see or what they notice with their eyes, instead of actually using more accurate reasoning to struggle through that. After several conversations, I’m really trying to, not necessarily force them, but require them to interact.