Abstract
There has been limited success teaching elementary students about the phases of the moon using diagrams, personal observations, and manipulatives. One possible reason for this is that instruction has failed to apply Gestalt principles of perceptual organization to the lesson materials. To see if fourth grade students' understanding could be improved, four lessons were designed and taught using the Gestalt laws of Figure-Ground, Symmetry, and Similarity. Students (n = 54) who were taught lessons applying the Gestalt principles scored 12% higher on an assessment than students (n = 51) who only were taught lessons using the traditional methods. Though scores showed significant improvement, it is recommended to follow the American Association for the Advancement of Science guidelines and wait until 9th grade to instruct students about the phases.