In order to achieve the goal and effect of classification and promotion, we should first give full consideration to students' great differences in knowledge ability, learning attitude and learning methods, while quality education requires us to face all students, so that each student's talents can be fully developed, and how to make top students eat well, middle students eat well and underachievers eat well. This determines that the current education must conform to the principle of teaching students in accordance with their aptitude and implement hierarchical teaching. The so-called hierarchical teaching means paying attention to both the similarities and differences of students in the same class and the individual development of students under the conventional class teaching system. Hierarchical teaching means that on the basis of students' stratification, teachers prepare lessons by stratification, teach by stratification and guide by stratification, so that students can practice by stratification, communicate with each other and develop together, so that students at different levels can achieve different teaching goals.

(A) the division of levels

To implement hierarchical teaching, we should first fully consider the different levels of students' intellectual development, so as to implement individual guidance according to students' excellent, medium and poor intelligence. In addition, some students have different cognitive styles when solving problems, so we should also pay attention to the differences in their existing subject knowledge base and the differences caused by different family backgrounds. Grasp the basic situation of the whole class and divide the students into three different levels according to a certain proportion: (a) solid foundation, strong acceptance, correct learning methods and excellent grades. (Grade B) Basic knowledge and intelligence are average, students are self-conscious and self-motivated, and their grades are average. (C) poor foundation and intelligence, weak acceptance, low learning enthusiasm and poor grades. For students' stratification, we use the methods of understanding, testing and discussing as the basis for dividing students' stratification. Tell parents and students in advance before stratification; Stratification is not an end, but a means