Abstract
Despite “waxing and waning of the moon” having being deleted from the elementary school science curriculum in1998, now it has again become a part of the current curriculum for the sixth grade. This program is designed for learning the principle of the Moon’s waxing and waning from the viewpoint of earth, while the program for 9th grade covers the one from the larger perspective of the universe.
However, a number of previous studies point to the difficulty of both teaching and learning of the theory, as well as instructors’ lack of knowledge. This research examines the reason for the problems mentioned above by analyzing the content of current elementary school science textbooks. The result indicates the difficulty of ensuring consistency between the observation of the moon as viewed from the earth and the model experiment, which is considered to derive from an insufficient theoretical explanation of both the position and distance between the moon and the sun as viewed from the earth as well as the waxing and waning of the moon. Thus, we developed and tested an instruction method which logically explains the waxing and waning of the moon and an intellectual machine as supplement material, by the use of which elementary student could comfortably understand the theory.
