Transcript:
"Once again, suppose that you have the chance to be a guest teacher of a three-day mathematics lesson to a class of fifth-grade students. The students' regular teacher wants you to help them understand the concept of volume. But she doesn't simply want the students to memorize the formula for volume - she wants them to be able to visualize what the concept of volume means. You'll have three class periods of instruction time on successive days, with each class period being approximately one hour. Your challenge is to identify essential concepts about volume that students can learn in those three class periods."