In the current mathematics teaching, there is a phenomenon that the teaching content is emphasized and the introduction is ignored. Teachers: because of the comparison of scores between schools and classes at all levels to evaluate teaching, and because of the pressure of entering a higher school, teachers are forced to continue to use the old teaching method, that is, "wearing new shoes and taking the old road", ignoring the "lead-in" link in teaching, thinking that lead-in is too time-consuming, so it is better to seize the time to teach this knowledge or strengthen practice; Some teachers also care about the lead-in, which can be simple or inflexible, such as: reviewing the relevant knowledge and content learned and transferring it from these preparatory knowledge to this class; Of course, some teachers have always attached great importance to classroom lead-in and accumulated a lot of valuable experience on the basis of practice. Especially with the gradual deepening of curriculum reform, classroom lead-in has been paid more and more attention by front-line teachers, and lead-in methods have been continuously introduced, which has achieved some good teaching results.

Students: First, the study burden is too heavy, and they think that mathematics is a boring subject, which leads students to lose interest in mathematics learning. Second, students need to attend seven classes every day, and they will feel tired both physically and psychologically. Third, junior high school students are curious. Therefore, students need lively classes; Teachers need to use lead-in to enliven classroom teaching atmosphere; Teachers need to skillfully design the lead-in, attract their attention, stimulate their interest in learning, and guide them into the state of learning preparation. Only in this way can teachers carefully design the lead-in, arouse students' curiosity with novel and interesting lead-in, enhance students' exploration psychology, thus attract students' attention and make them enter the learning state quickly. This is what students really need in math class. Therefore, junior high school mathematics classroom needs the introduction of characteristics. How to design classroom lead-in, attract students' attention and stimulate students' interest in learning has become an urgent problem for our front-line teachers. I. Purpose and significance of the study

It is generally believed that it is very important to attract students' attention at the beginning of new teaching content; Curiosity is the most realistic and active component of learning motivation; Lead-in should construct learning objectives, make students enter a good state of psychological preparation, and concentrate on meaningful learning; The connection between old and new knowledge should be established in the import, so that the new lesson can be imported smoothly. That is to talk freely with students, teachers and students get to know each other, and introduce any content in the classroom from topics familiar to students in daily life, so that they can not only establish friendly relations in a relaxed and lively atmosphere, but also learn new knowledge naturally in this class and carry out divergent thinking. And attract students' attention in a concise and clear way, so as to effectively carry out classroom activities. Promote them to enter a good state of psychological preparation, thus establishing the connection between old and new knowledge and naturally introducing new courses. Second, the theoretical basis of the research

Ganegan, a famous scholar, divided the whole teaching process into nine stages: attracting attention, informing goals, creating knowledge, presenting teaching materials, providing learning guidance, exporting homework, providing feedback, evaluating homework, and promoting maintenance and migration. Attention is the primary factor in the teaching process. From the point of view of information processing, if individuals do not pay attention to the stimulus information acting on sensory organs, then these information will be forgotten in a very short time. The basic purpose of knowledge teaching is to enable students to store knowledge in long-term memory; Because only by storing the long-term memory knowledge can students use it to learn new knowledge or solve problems. Therefore, teachers must consider how to attract students' attention to learning at the beginning of the teaching process, that is, classroom introduction. Furthermore, the aesthetic psychology in aesthetic requirements consists of various psychological elements such as perception, emotion, imagination and understanding. In the sense of beauty, vision and hearing are the two most important. Aesthetic feeling has the characteristics of keen selectivity and integrity; Emotion, imagination and understanding participate in aesthetic feeling, among which emotion plays the most obvious role. The classified query of periodical articles is based on the characteristics of aesthetic psychology of periodical libraries, which enlightens teachers that the design of classroom introduction should follow the principles of novelty, pleasure, intuition and aesthetics.

Third, research methods (1) literature method: consult and collect monographs, papers and materials related to this research topic by domestic and foreign scholars. Through library consultation, academic journal network, Tianyu database, Wanfang database, online search and other ways to understand the import design and related articles, understand the predecessors or their research work, clarify the scientific value of the research topic, find the breakthrough point, and obtain newer and more valuable research results.

(2) Content analysis method: Collect a large number of typical introduction cases in junior high school mathematics classroom and make an all-round analysis.

(3) Educational experiment method: Apply carefully designed lead-in cases to practical teaching.

(4) Questionnaire survey: To investigate the extent to which classroom lead-in has stimulated students' interest and enthusiasm in learning and students' satisfaction with classroom lead-in.

(5) Interview survey method: Collect data through direct face-to-face conversation with students. Understand the effect of lead-in design in teaching practice and your own views and opinions. Iv. main research contents 1. A case study on the introduction of typical mathematics courses in junior middle schools.

(1) The role of lead-in in junior high school mathematics classroom can stimulate learning motivation; The function of promoting intellectual development; The function of stimulating interest; Connecting the preceding with the following, learning new things from the old; The function of regulating learning mood; Give play to the role of aesthetic feeling. (2) Types of introduction in junior middle school mathematics classroom. Handling the lead-in well can stimulate students' enthusiasm, generate strong interest and receive good teaching results. That's for sure, but what kind of introduction method should be carefully considered. We must never adopt a fixed pattern or copy it mechanically. Different subjects, different textbooks and different students should choose different types. According to some examples in mathematics teaching, there are the following methods: discovery method and introduction method; Interesting introduction method; Question introduction method; Analogy introduction method; Intuitive introduction method; Game introduction method; Problem introduction method; Situational introduction method; Cohesion introduction method; Case introduction method, etc. , but also according to the characteristics of junior high school students, for specific teaching content, design a distinctive lead-in. According to certain dividing standards, the mathematics classes are classified. According to the characteristics of mathematics; The goal requirements of mathematics curriculum reform; Psychological and behavioral characteristics of junior high school students; Teachers' own advantages and characteristics. The members of the research group design classroom lead-in for different class types, then discuss and revise collectively, and then form teaching plans for classroom practice.

By collecting a large number of typical lead-in cases in junior high school mathematics classroom and analyzing them comprehensively, the principle behind these cases is preliminarily explored; The introduction methods in these cases are classified to provide ideas for designing effective introduction methods suitable for junior high school mathematics classroom. According to the characteristics of junior high school students, according to the specific mathematics teaching content, design a distinctive lead-in. Attract students' attention and stimulate their interest in learning through lead-in, so as to improve the quality and efficiency of mathematics teaching. The research results have a certain guiding role and good reference value for junior high school mathematics teaching practice.