This document provides a teacher's guide for a classroom unit to help students understand the phases of the moon through hands-on modeling and reading a book. The unit has three main objectives and involves students standing in a circle around a light bulb representing the sun to demonstrate the moon's orbit and changing phases as it revolves around the earth. At each of eight stops representing a moon phase, students observe the illumination on their model moon and the teacher reads from the book to describe that phase.