The Modern Chinese Dictionary gives a clear answer: "The process of students learning the text to be heard in advance is preview." The process of preview is the process of self-study, that is, the process of finding, analyzing and solving problems independently based on their existing comprehensive ability, and the process of students understanding and memorizing knowledge independently. Preview is an extremely important stage in learning, which is characterized by being one step ahead and its essence is autonomous learning. In this sense, preview is the first core of learning. Preview in the process of students' learning can make students have an important link and an appropriate general understanding of what they will learn before class; Students attending classes with questions can improve the efficiency of attending classes.

Two: Why should we implement "preview before class"? What are the important functions of "preview before class"?

Preview is one of the methods to cultivate students' self-study ability, and it is also an important link to expand students' thinking ability and imagination ability. It can encourage students to study actively, improve the quality of classroom teaching, and stimulate students' curiosity and interest in learning. The new curriculum standard advocates preview, which is a learner's independent exploration activity. Students rely on existing knowledge, life experience and learning methods to explore independently, thus stimulating students' interest in learning, enhancing their confidence in learning mathematics well and promoting development. The new curriculum standard also puts forward different levels of preview and reading requirements for students above grade two in senior high school. Under the background of the new curriculum concept, preview is no longer just a learning activity to master knowledge and skills, but to make every child develop better. It can be said that preview is an indispensable link in the teaching process. The important role of preview before class is mainly manifested in the following four aspects:

1. preview can improve the initiative and enthusiasm of learning, and change passive indoctrination into active acquisition;

2. Preview can improve the efficiency of class and turn eating and drinking in class into chewing slowly before class;

3. Preview can enhance students' self-confidence and turn confusion into self-confidence;

4. It helps to cultivate independent thinking ability and preview before class alone.

Third, how to cultivate primary school students' math preview ability? What are the general gradual steps?

In the initial stage, the main starting point is to guide students' preview methods and cultivate students' preview habits. The guidance of mathematics preview method can be divided into the following four steps:

1. Read through the math content, circle the knowledge points and understand the main content.

2. Read the content carefully to understand the main mathematical knowledge. This is the main link of preview, that is, after students have a certain understanding of the previewed mathematical knowledge, teach students the method of "digesting" these knowledge. These methods mainly include: (1) listing familiar cases to understand concepts and concretizing abstract concepts; (2) Hands-on experience of mathematics; (3) Boldly try to answer examples to think about problems; (4) Clever use of comparative analysis.

3. Intensive reading of difficult contents, thinking and marking doubtful points are important parts of math preview. With questions, students have goals in learning new lessons. Preview is the process of discovering doubts.

4. Try to practice and test students' preview effect, which is an indispensable process of math preview.

Four: the guidance of typical preview methods of primary school mathematics.

According to the characteristics of primary school mathematics textbooks, the age, psychological characteristics and cognitive rules of primary school students, the following preview methods are taught to students:

1. Implement the preview method of "Guide Sheet"

2. Reading comprehension-try to practice.

3. Hands-on operation-experiment summary

4. Systematic induction-learn new formulas by reviewing old friends.

5. Material preparation

Step 6 work in groups

Five: What should we pay attention to in cultivating pupils' preview ability?

As learning individuals, students have their own differences. Under the condition of class teaching system, how to make every student really participate actively and get different levels of development. Through practice, we found that in the initial training of primary school students' preview ability, the following points are worth noting:

1. Guide students to preview. According to the characteristics of primary school students, the preview design before class should have a clear purpose and operability, and there should be no preview requirement of "previewing the textbook from page X to page X".

2. Pay attention to cultivate students' habit and interest in preview. Because primary school students are beginners, they don't know how to preview mathematics, and they don't have the habit and interest to preview actively. By encouraging timely evaluation of good preview methods and effects, students can feel the joy of success and design various preview questions, which can gradually develop the habit of preview before class and stimulate students' interest.

3. Allow different students to have different preview effects. The new Curriculum Standard points out: "Mathematics education should be geared to all students, recognizing that different people have different development in mathematics", "We should correctly understand students' individual differences and teach students in accordance with their aptitude, so that each student can develop on the original basis, so that students can gain successful experience and establish self-confidence in learning mathematics well". Recognize students' individual differences, allow students to have different preview effects, and don't force students to reach the same level for preview effects.

4. According to different teaching contents, design preview questions and guide preview methods. Fully prepared, carefully designed questions, let students read with questions, let students know the content before the teacher speaks new knowledge, find problems by themselves, and solve some problems within their power, which not only exercises students' thinking ability, but also reduces classroom pressure.

5. Pay attention to the feedback function of preview homework, further determine the key and difficult points of the classroom, the capacity of classroom knowledge and the teaching progress, change the rigid and blind teaching mode of teachers and teachers' subjective presupposition in traditional teaching, truly achieve a targeted goal, and make the classroom a place for two-way communication between teachers and students. The teacher is determined not to talk about the students' complete understanding, and the students' basic understanding is supplemented slightly. Let the students who don't understand at all or most of them make breakthroughs in key topics, so as to optimize the teaching process and improve teaching efficiency.

6. The purpose of preview is not only to serve teachers' teaching, but more importantly, to promote students' autonomous learning and achieve all-round development.

In short, junior students should pay attention to the cultivation of preview interest and preview habits, while middle and senior students gradually turn to pay attention to mathematical thinking and