The purpose of this study is to enhance the achievement in mathematics by developing compensatory learning materials and applying those to learning. The conclusions of this study are as follows. 1. Solving the learning tasks by cooperative learning guided instruction to learning by students from teaching by teacher, and it made learning effective and students cooperative in personal-relation 2. Learning materials for compensating learning deficit made students motivated and interested in mathematics, and active in learning. 3. By applying the learning materials for compensating prerequisite learning deficit, students could grasp learning contents and learning tasks, and their achievement could be enhanced. On the basis of problems which appeared in the progress of this study, the suggestions are as follows. 1, The necessity of mathematics in agricultural high schools should be recognized by students and various learning materials should be developed. 2. In cooperative learning, the roles of team-chiefs have a great influence on learning mood and problem-solving processes, they, therefore, must be directed beforehand so that they play the roles of leaders.