In the present study, the authors practiced using a combination of newly developed model teaching aids of the moon's movement and observations to determine the effects on the level ofelementary education program students' understanding of the moon's appearance or phases. The content of the practice had two parts. One was to record periodical moon observations; the students were to record the waxing and waning of the moon for two consecutive days. The other was learning using the newly developed model teaching aids. The effects of the practice were evaluated by a questionnaire measuring the understanding of the positions and phases of the moon before and after the practice. As a consequence, the following findings were obtained: (1) The percentage of students who correctly described why the observed shapes of the moon looked different from day to day, as well as describing the revolution of the moon around the earth and the reflection of sunbeams, increased significantly compared to the prepractice rate. (2) The rate of correct answers to each of the following questions significantly increased when compared to the pre-practice rate: "In which direction did you see the full moon after sunset?" ; "In which direction did you see the crescent moon after sunset?" ; and "Tell thepositional relationship between the sun and the moon when the waxing moon was observable after sunset." (3) It was thus found that the use of a combination of the newly developed model teaching aids of the moon's movement and observations improved the level of elementary education program students' understanding of the moon's appearance or phases.