Mathematics is an accumulation of graded and sequential mathematical concepts that the learner acquires with great care in order to deal with the material easily and conveniently. Building mathematical concepts has the most important stage in learning the material. Do not forget that mathematics has strong relationships with all sciences. I suggest at the outset diagnosing the extent of the learner's acquisition of mathematics, each according to his educational level, and then I will identify the stumbling blocks and concepts that the learner will proceed to overcome smoothly.