抄録
In this study, the significance for instructing the projection which was elicited in the current course of study and will be reappeared in the next course of study is reconsidered. In addition to this, the efficient of the instruction with using painted projection which was developed in the area of space geometry in the seventh grade. In the sketch and projection which was treated in Japan, the spatial elements, such as the shape, size and position are given to the students, but the color is not considered much. The materials which were developed have big characteristic. When the students have to express the solid which was painted by three colors (red, blue and green) through the sketch and projection superficially or guess the stereogram characteristics from the sketch and projection, they have to take the colors into consideration. Taking the colors into consideration make the students enhance and enrich the figure concepts. The teachers can instruct the students from inductive guessing to deductive guessing smoothly by making the students express the process and validity for guessing. Two results were got through three classes for seventh graders at junior high school attached a university. One is that the class in which this learning material was used makes the students enhance the change of viewpoints and the way of thinking for the unification. The other is that the class has the effect by activating the communication in which the reason was clear. Totally the class can cultivate the basic of the proof which the eighth graders will learn. Moreover, it is expected that treating the color which is not taken into much consideration in math makes the communication active and form the way of mathematical thinking as a result. This point is going to be researched.
