It is one of the clearest teaching methods to find out the key points, difficulties and the connection points of knowledge before and after, and to bring forth the new through the old. What you learn today should pave the way for what will happen tomorrow. Today's knowledge is the development of yesterday's knowledge. Just like a series of books, we should find out the internal relationship between knowledge, and don't grab it with eyebrows and beards. One lesson is the focus of all. For example, the writing multiplication of multiple digits multiplied by one digit is learned on the basis of table multiplication and oral calculation of integer ten and hundred digits multiplied by one digit; It is also the basis of multiplying multiple digits by two digits and three digits. How much is China Children's Books for two copies in 3 yuan? 3×2=6 (yuan) 10 How much is the copy? How much is 3× 10=30 (yuan) 100? 3× 100=300 (yuan) Reviewing the multiplication in the table and the oral calculation of multiplying integer ten and positive percent by one digit through these three questions is the basis of "writing multiplication of multiple digits multiplied by one digit"; What is 12? 3× 12=36 (yuan) 2 12 How much is the copy? 3×2 12=636 (yuan) Through the above two questions, the written multiplication of multiple numbers multiplied by one number is derived, that is, the newly granted content. This part of knowledge is the continuation and development of multiplication in tables and oral calculation of integer ten and integer multiplied by one digit. The newly authorized pen multiplication of multiple digits by one digit is the basis of future pen multiplication of two digits by two digits, three digits by two digits, and even multiple digits by multiple digits. Only by figuring out the algorithm of pen-style multi-digit multiplying by one digit can we figure out the algorithm of pen-style double-digit multiplying by two digits, three-digit multiplying by two digits or even multi-digit multiplying by multiple digits. For example, 12× 13, 2 12× 13 knowledge is interrelated. We can't see the forest for the trees. Isolated lectures will make teachers and students tired and inefficient. It is particularly important to know the ins and outs of new knowledge before preparing lessons. Second, look at the textbook and read the textbook:
Seeing that teachers know the important and difficult points and the position of knowledge in the whole system, we can have a macro positioning; Then reading the textbook is to understand the writing intention of the textbook from a micro perspective. We must understand and learn textbooks, so that we can make good use of the medium of textbooks to break through difficulties, complete teaching tasks and realize efficient classroom. For example, in the teaching of oral multiplication, 20×3=60 200×3=600 2000×3=6000. Some teachers sum up the algorithm, if there are several zeros at the end of the factor, add a few zeros at the end of the product. On the surface, there are several zeros in the numerical factor, but in fact, 60 is six tens. Six hundred is six hundred; 6000 is 6000, so there are 1 zeros, two zeros and three zeros at the end of the product. Finally, the zeros at the end of the product will belong to the counting unit. If the mathematics is clear, students will not have the phenomenon that 20×5 has 20×5 = 10, and they can't just have a half-knowledge of the textbook. Reading textbooks is the key to ensure effective lesson preparation. Third, prepare students:
1. See if students have mastered or partially mastered the knowledge and skills required by the teaching objectives, to what extent, and what knowledge they have not mastered. 2. What new knowledge students can learn independently and what needs teachers' guidance and guidance determines which knowledge should be focused on and which can be ignored. 3. Pay attention to individual differences, design different levels of problems in classroom teaching, so that students with strong ability can develop their thinking, students with medium ability are interested, and students with poor ability can master methods, so that students with different levels can be improved accordingly. Design classroom exercises are divided into three levels, namely, basic exercises, variant exercises and expansion exercises. Through stratified practice, all kinds of students can learn something and arouse their learning initiative. Fourth, calculate and ponder the exercises in the textbook in advance:
It is necessary to ensure that an efficient math class is prepared, the exercises after class are calculated and pondered in advance, and the problems encountered are combed and refined. Doing exercises in advance is very helpful for grasping difficult and error-prone questions, which will allow us to fully consider the problems in exercises in the process of preparing lessons and make targeted presuppositions in the teaching process. V. Preparation of teaching methods: (1) Preparation of situation creation The prepared situation creation is the background of mathematics activities, and a good beginning is half the battle. Scene creation can be a scene of cognitive conflict, which makes children wander in the contradiction of thinking and produce the idea of finding out; It can be a state of creating suspense, being close to the child's heartstrings and generating curiosity; It can be that life examples are introduced into the classroom, so that children can feel the value of mathematics from the beginning and have a desire to learn; It can be in the form of stories, riddles and so on. Regardless of emotion, context, doubt and interest, it is to arouse students' interest in learning and sprout a desire to learn mathematics knowledge. For example, a teacher in The Stability of Triangle said that at the beginning of class, the teacher put a chair that was about to fall apart in front of the students. "There is one thing I want to ask my classmates for help. This chair is shaking and needs reinforcement. Where does this kind of wooden nail apply? After heated discussion among the students, there are three situations. The teacher said, "where can I nail that chair that is about to fall apart?" "With this question, why don't we learn the knowledge of triangles together? You will be pleasantly surprised." The teacher didn't talk much but made psychological preparation and knowledge preparation for the study of new knowledge, and the students entered the exploration of learning knowledge with questions. (2) Effective question preparation is the key to inspire students to think positively, arouse their learning enthusiasm and improve classroom efficiency. However, many times we ask too many questions, too few, too shallow and too common. In order to avoid questions like "yes", "yes" and "yes", students only need to answer "yes, yes and yes", which can't really arouse students' interest. Some questions are too open to be explained clearly; Some questions are not hierarchical and the difficulty is not accurate. Therefore, we try our best to ask enlightening questions on the growing point of new knowledge-laying bridges; Ask carefully about the important and difficult points of knowledge points-clear your mind; Asking questions skillfully in finding the law-setting doubts to stimulate interest; Ask questions in the difficult and confusing places of thinking-point out the ideas and highlight the essence. (3) The mastery and consolidation of new knowledge or new method preparation exercises need to be completed through certain exercises. However, because 40 minutes in class requires new Protestant practice, the time is tight, so our practice must be carefully designed, targeted and purposeful, and the form of practice should be basic practice, variant practice, comprehensive practice and so on. (4) Breakthrough in preparing for the exam The breakthrough in key and difficult points is the core of a class. Whether it is handled properly directly affects the success or failure of a class. No matter how good the situation is, no matter how wonderful the problems are, we can't break through the difficulties. Everything has become a formality. (1) Take the old with the new, and make a breakthrough in migration; (2) Transformation breakthrough; (3) intuitive demonstration and drawing breakthrough; (4) breakthrough in formula; (5) Looking for the prototype of life and breaking through difficulties. In short, high-quality lesson preparation will have an efficient classroom, and lesson preparation should be "four preparations", that is, preparing people, books, methods and exercises; "Four points" means highlighting key points, dispersing difficulties, analyzing doubts and grasping key points; The "four good" courses are well defined, the topics are set, the training is arranged and the language is honed. Careful preparation of lessons can lead to wonderful and efficient generation.