Elements of difficulty level in mathematics

It is important for each leader to know relationship of the reason why each learner mistakes the problem of Mathematics. But, it does not exist about previous research. Therefore, in this research, we collected answers of each learner for knowing element of difficulty level in Mathematics. And we identified 10 types. 10 types are “lack of understand(problem statement, Number & Symbol, Formula, Concept)”, “circumstances of learner (inside)”, “circumstances of learner (outside)”, “Miscalculation”, “Copy miss”, “Lack of logical thinking (Deduction)” and “Lack of logical thinking (Induction)”.