Much of the knowledge in primary school textbooks belongs to transfer textbooks, and students already have the foundation to learn new knowledge. The presentation of examples is also suitable for students to "preview", and most examples leave room for students to think.
Often see such a scene, the teacher always forgets to add a sentence when assigning math homework: "Go home and preview what you will learn tomorrow." This sentence has almost become the "mantra" of many teachers, but do students know how to preview? Pupils are young and have limited ability, so they often don't know where to start when preparing for classes. Many students simply understand preview as reading math books and skimming while learning, so it is difficult for them to think independently in textbooks and actively explore new knowledge. Some students think that the exercise at the end of the book will be done. Taking preview as a boring task will cause students' interest in learning mathematics to decline over time. Therefore, teachers should guide preview methods step by step, set up preview instruction classes when necessary, select representative content in the class, create preview situations before class, guide students step by step, and let each student master preview methods. You can use four steps to design the preview questions: what to do-how to do it-why to do it-and what is not clear.
Provide preview guidance courses. Select representative content in class, create preview situations at home, and guide students to preview step by step. For example, in the lesson "Year, Month and Day" in the sixth volume of primary school mathematics, let students preview this content from the following four steps:
(1) Read the contents of the textbook for the first time and understand the main contents. (2) Read the textbook carefully and understand the meaning of each sentence. Underline the sentences you don't understand. (3) Think about it, where is the new knowledge? What does it have to do with old knowledge? (4) Give it a try. Can you do the exercises in the textbook? What are the reasons for doing so? Leave 20 minutes for students to study by themselves first.
First, with the "problem" as the main line, scientifically organize preview.
"Preview" is essentially a self-study activity under the indirect guidance of teachers. The preview process begins with "questions" and ends with "questions". Students start self-study according to the teacher's questions or tips, and gain a preliminary understanding of new knowledge by thinking about the teacher's questions and relying on old knowledge and experience. At the same time, they ask the teacher questions, puzzles, new ideas and new insights during the preview process.
We can take the third grade as the starting point for students to learn to preview mathematics. At the beginning of training, teachers' leading role should be highlighted. Teachers can arrange appropriate time in classroom teaching so that students can preview under the guidance of teachers. They should put forward clear preview requirements and steps for students and teach them specific preview methods. For example, before learning The Perimeter of Rectangle and Square, I ask students to preview it like this: 1, read pages 47 to 48 of the textbook, draw the sentences you think are important as a straight line, and read them several times to see if you understand them; Mark what you don't know. 2. Look for squares and rectangles around you, measure and calculate, see what you find and write it down. Talk to your classmates about the discussion questions raised in the textbook. 4. "Do it", ok? Please do your best. Read the book again, talk about what this section focuses on, think about any difficulties and write it down. In the fourth grade, you can "put preview activities outside class", but before each class, you should give students "preview tips" to guide students to preview according to preview tips and combined with the methods they have learned, so that students can preview independently along the way.
1. Carefully design preview questions
Preview questions are the basic "support" for students to preview themselves, and proper design of preview questions is the key to achieving good preview results. Good preview questions can guide students to learn by themselves and inspire their thinking.
(1), the preview questions should be operable.
When arranging the preview homework, we should not only prevent the vague preview requirement of "please go back and preview a few pages or pages today", but also not design the problem too big. Teachers should be good at breaking down the preview requirements into several small points or presenting them with several small questions, so that students can learn by themselves according to the preview questions.
For example, to teach the characteristics of multiples of 2 and 5, the Preview Outline is arranged as follows: 5 on p4-5.
What are the characteristics of multiples of 1 and 5?
2. What is an odd number? What is an even number?
What are the characteristics of multiples of 3 and 2? Circle a multiple of 2 on page 4 of the book.
4. Difficulties: What are the characteristics of numbers that are both multiples of 2 and multiples of 5?
5. Try to answer: "Practice" on page 5 of the textbook.
6. Think about it: If you have any questions, please write them down in your notebook and ask questions in class.
(2) Preview questions should reflect their own abilities.
Through preview, students can really understand and solve some problems, but through preview, teachers should not only know what problems students can understand and solve, but also have more accurate estimates. They can't simply confuse the teaching goal with the preview goal, and put forward some unreasonable requirements, which will dampen students' enthusiasm for preview.
(3) Preview questions should be enlightening.
The process of preview is the process that students try to understand new knowledge and solve new problems. Guiding preview questions help students understand new knowledge and strive for success.
For example, preview "Decimal divided by Decimal". Because students have mastered the calculation method of dividing decimal into integer, the key to new knowledge is to use quotient invariance to convert divisor into integer. You can design a preview question: Quadruple p64.
(1) read p64 "who calls for a long time".
(2) Read carefully what "Xiaoxiao" and "Smart Dog" said, and talk about how to change the dividend and divisor to keep the quotient unchanged.
③ How to convert fractional division into integer division? What are the rules?
(4) Complete the blank part in the calculation.
⑤ Try it: 9 1.2÷3.8.
(4) to adapt to the class, grasp the adaptability of preview.
Some textbooks are detailed and intuitive, closely linked with students' old knowledge and experience, which is conducive to students' self-study; Some textbooks are short and abstract, which is not conducive to students' self-study; Even in the same class, there will be some content suitable for self-study and some content suitable for explanation. Therefore, it is not appropriate to classify some abstract contents that are explained by teachers and difficult for students to understand as unified preview contents.
2. Reasonably determine the preview form.
"Reading" (reading), "thinking" (thinking about teachers' questions), "trying" (imitating exercises and trying to do) and "asking" (students asking questions or new ideas) are the basic forms of primary school mathematics preview, but the preview homework must not fall into the trap of blindly paying attention to imitation questions. Combined with the specific preview content, you can focus on reading, thinking, trying or asking questions.
In addition, special preview forms can be designed for different teaching contents, such as:
Data collection: for example, arrange students in front of teaching quality unit and volume unit, and collect relevant data from relevant objects.
Access to information: For example, arrange for students to access Zu Chongzhi's information before teaching PI.
Making and observing: For example, before teaching cuboid, cylinder and other three-dimensional graphics, arrange students to make learning tools and observe their characteristics.
Experiment and writing experiment report: for example, arrange students' experiments and write experiment reports before teaching the volume relationship between cone and cylinder.
In short, the forms of preview should be diversified, students' ability points should be identified, students' interests should be targeted, and students should be allowed to preview actively.
Second, choose the appropriate preview method. Because students are young and lack of experience in acquiring knowledge, it is very important to give them scientific guidance on preview methods, which is directly related to the success or failure of preview and the formation of preview habits.
(1), Preview of Mathematics Concept Course
Let the students draw and circle the main points and contents of knowledge on the basis of reading the new lesson. In this process, students can perceive new mathematics knowledge as a whole, draw a picture, circle the concepts and conclusions that they think are important, and make the main contents of the new lesson appear, thus attracting their attention and preparing for further understanding and mastering new knowledge.
1) Give examples to understand the concept. Mathematical concepts are not created out of nothing, but abstracted from the concrete real world. Of course, we can find the prototypes of these concepts around us. For example, when previewing the operation law of multiplication, let students give some concrete examples to illustrate the concept, which can help students understand the concept intuitively.
② Hands-on practice to feel the concept. Hands-on practice, independent exploration and cooperative communication are important ways for students to learn mathematics. Students should also guide students to understand mathematics knowledge through hands-on practice when previewing. For example, when previewing the sum of internal angles of triangles, let students cut and paste and spell, so that students can not only be interested in mathematics learning, but also naturally understand and master the knowledge that the sum of internal angles of triangles is 180 degrees.
③ Clever use of contrast to analyze the relationship. In the study of mathematics, comparison is a very important and frequently used learning method, and so is preview. For example, when previewing decimal addition and subtraction, let students compare calculation rules, operation rules and some problems that should be paid attention to with integer addition and subtraction, and find out their differences and connections. This not only reveals the relationship between old and new knowledge, but also helps students form a knowledge network.
(2) Preview of the course of mathematical calculation
1 understand the example. Whether it is a new textbook or an old textbook, the calculation method will be presented in the form of examples in the arrangement of calculation courses, which provides a platform for students to preview. Students can master these methods to a great extent through preview. In class, we can concentrate on solving problems that students have not solved in preview, and we can learn more deeply and widely.
② Summary algorithm. There is more than one way to solve many practical problems. Students should think about different problem-solving methods, optimize algorithms and gradually improve their logical thinking ability in preview.
② Try to practice. By trying to practice, students' preview effect can be tested, which is an indispensable process of math preview. Students have initially understood and mastered new mathematics knowledge through their own efforts, so students should test their preview effect by doing exercises or solving simple problems. It can not only make students reflect on the loopholes in the preview process, but also let teachers find the key issues that students pay attention to when learning new knowledge, so as to grasp the important and difficult points in classroom teaching and explain them.
(3) Preview of math operation class
The implementation of the new curriculum requires students to learn mathematics knowledge, not only to know why, but also to know why. Only when students have experienced the process of forming mathematical knowledge can they know why. It is inevitable to do it by themselves and try it by themselves. Because there is hands-on content in the class, it is inevitable to be familiar with the teaching materials, understand the tools and materials needed in the operation process, and make preparations before class. For example, when teaching statistics, let students count the family expenses for one month. At this time, we can take it as a preview and let them finish it before class.