First, situational guidance, the concept of discovering essence is a summary of the essential attributes of the research object. The generalization process of essential attributes is a thinking process from perceptual to rational, from special to general. In order to make students get a clear concept, it is necessary to fully carry out such a process in concept teaching. According to the age characteristics of junior high school students, we should try our best to introduce concepts in combination with their real life experience, so that students can influence concepts subtly, instead of following the book. Memorize words and phrases. For example, when teaching the concept of rectangular coordinates of points in the plane, it is essentially based on the one-to-one correspondence between points in the plane and ordered real number pairs. We can introduce the topic with some familiar examples such as students watching movies and finding seats, so that students can learn new concepts unconsciously instead of memorizing concepts. Of course, it is not an end in itself. It is only a means to achieve the teaching goal. In order to explore the abstract essential attribute of the research object with vivid examples, we should focus on how to raise perceptual knowledge to rational knowledge. In addition, examples in life are not equal to mathematical concepts, some contain non-essential attributes, and some omit some essential attributes, so teachers must be practical when giving examples to prevent students from misinterpreting concepts and going to the other extreme. In the process of concept teaching, concepts should be formed in the concept system, not suddenly instilled in students. From the introduction of original concepts, we should not only pay attention to introducing new concepts on the basis of students' existing knowledge, but also fully reveal the contradiction between new knowledge and old concepts, so that students can realize the limitations of old concepts and the necessity of learning new concepts. This requires us to analyze the position of new concepts in the concept system well before teaching. For example, the position of the arithmetic root in the textbook is the square root in front and the root in the back. It is convenient to study the properties of roots and perform root operations, because the square root of a positive number has two values, and the two values are opposite. Therefore, we only need to study the properties of quadratic root. The appearance of arithmetic root solves the feasibility and singleness of square root operation in real number range, thus paving the way for studying root. It plays a connecting role in the conceptual system. Second, putting forward the definition and promoting the understanding of the concept definition is a summary of the essential attributes of our research object. The wording is more refined and each word has its important role. In order to deeply understand the meaning of concepts, teachers should not only pay attention to the rigor and accuracy of words used in concept discussion, but also correct some improper conceptual mistakes in time, which is conducive to cultivating students' strict logical thinking habits. Gradually develop the good habit of delving into definitions, word-for-word analysis and careful deliberation. For example, when explaining the concept of isosceles triangle, we must emphasize that there are two equilateral words "You" in the concept, not only two equilateral words "Only". The first two equilateral sides include two situations: one is an isosceles triangle with only two equilateral sides, that is, an isosceles triangle with unequal waist and bottom; Second, an isosceles triangle with three equilateral sides is also called an equilateral triangle. The latter involves only one case, excluding the special case that an equilateral triangle is also an isosceles triangle. Another example is "A, B and C are not all equal to zero" and "A, B and C are not all equal to zero". These two words are the same, but in different positions, but with completely different meanings. Another example is "three", which is not on the same line. A new proposition is obtained, which includes two cases: three points are on the same line and three points are not on the same line, but three points on the same line cannot determine a circle, that is, any three points on the circle are not on the same line. Therefore, writing three points determines a circle, and no three points are on the same straight line. Therefore, when talking about this concept, we should emphasize the sentence "not in a straight line". Some concepts are simply difficult for students to accept and master. However, if some related or relative concepts are put together for analogy and comparison, so that students can understand their relationship and notice their differences, they will find another way. The relationship between two concepts can be divided into two types: compatibility and incompatibility, and compatibility can also be divided into three types: the relationship between positive integers and natural numbers is the same. Square root and arithmetic square root are subordinate, square root and radical form cross, rectangle and rhombus cross, parallelogram and trapezoid are incompatible. For another example, when it comes to elevation and depression, it is not difficult to distinguish who is elevation and who is depression. Another example is the central angle and the circumferential angle. Most students can get the definition of "fillet": the angle of the vertex on the circle is called "fillet", which is wrong. At this time, the teacher will describe the definition of "rounded corners", and students will feel suddenly enlightened. By comparing the concepts of "central angle" and "central angle", it is clear. A deep understanding of mathematical concepts is the basis of improving students' ability to solve problems. On the other hand, only by solving problems can students deepen their understanding of concepts, so as to understand and master the connotation and extension of concepts more completely and profoundly. There are many examples of solving problems directly with concepts in textbooks, so we should make full use of them in teaching. At the same time, for the concepts that are prone to misunderstanding, we should design some targeted topics for students, so that students can understand the concepts more thoroughly through practice and evaluation. Mathematical concepts that reveal the essence are the basis of mathematical thinking. In order to make students have a thorough and clear understanding of mathematical concepts, teachers should first deeply analyze the essence of concepts and help students understand the connotation and extension of a concept, that is, clarify the objects reflected by the concept from both qualitative and quantitative aspects. For example, mastering the concept of vertical includes three aspects: ① understanding the background of introducing vertical lines: when one of the four angles formed by two intersecting lines is a right angle, the other three are also right angles. This reflects the connotation of the concept. ② Knowing that two straight lines are perpendicular to each other is an important special case of the intersection of two straight lines, which embodies the extension of the concept. ③ Reasoning by using the definition of two perpendicular straight lines shows that the definition has two functions of judgment and nature. In addition, students should learn to solve problems with concepts and deepen their understanding of the nature of concepts.