Abstract
The final purpose of this research is to develop the school mathematics curriculum of geometric figure in compulsory level based on the theoretical framework in order to mediate between elementary and secondary school mathematics, according to Okazaki & Iwasaki (2003). For attaining this purpose, this paper describes a experimental study on the fourth grade's lesson on geometric figure, whose focus is to promote the awareness of the properties of geometric figure. The characteristics of children who are promoted the awareness of the properties of geometric figure are as follows in concrete terms: (1) to be able to give the properties of geometric figure which is presented, (2) to be able to remind the geometric figure and to give other properties of it when some properties are presented. We developed the teaching-learning materials to promote the awareness of the properties of geometric figure and implemented those materials in the fourth grade's lesson. The effectiveness of the developed materials and the lessons were evaluated by the use of the performance task right after lessons and six months later. The result of the evaluation shows us that the developed materials and the lesson design are effective to promote the awareness of the properties of geometric figure and have a lasting effect for a half year.