Unit 4, Book 12 of primary school mathematics is always reviewed, with the emphasis on "reason". That is, combing the context of knowledge, combing all kinds of problem-solving ideas and methods, as well as their internal relations and differences. Pay attention to the systematic arrangement and induction of knowledge, make it organized and systematic, and form a relatively complete knowledge system. However, the focus of review teaching is not only to organize knowledge, but more importantly, to cultivate students' ability to solve practical problems flexibly by comprehensively applying the knowledge and methods they have learned. Therefore, on the basis of fully grasping students' knowledge level, we should draw up the review focus, remedial measures and methods and conduct targeted review; It is necessary to consolidate and deepen the knowledge learned, and at the same time enable students to master the connections and differences between various parts of knowledge; Let all students improve on the original basis.
As far as the arrangement of review textbooks in this unit is concerned, it is not only the arrangement and combination of knowledge, but also the guidance of teachers and students in thinking, speaking, discussing, arguing and moving, the presentation of knowledge points in review, the form of practice test and so on. , are closely around to let students master the relationship between knowledge, build a cognitive system, divided into six parts, so that knowledge is orderly. At the same time, we can create good materials for review by guiding students to actively participate in the review process, reflecting students' thinking process of acquiring knowledge, cultivating students' mathematical consciousness and improving students' ability to use knowledge flexibly.
The quality and effect of review are largely related to teachers' understanding of textbook arrangement, students' knowledge, selection of review methods and design of review content, and students' enthusiasm for participating in review. Therefore, according to the actual situation of the students in this class, I have done the following work:
(A) review and form a system
Mathematical knowledge is very logical and systematic. When reviewing, students should be guided to review and sort out step by step according to the logical order and internal relations of knowledge itself, with emphasis on students' understanding and mastery of conceptual meaning, so as to clearly and completely grasp the structure of knowledge and enable students to understand and master knowledge more deeply.
(B) highlight the comparison, communication and contact
When reviewing, teachers should not only carefully design questions, but also inspire and guide students to do a good job in the knowledge content directly compared in these textbooks, pay attention to the comparison of the contents of those text prompts in the textbooks, and consciously let students practice changing conditions and problems for some examples or exercises in the review, so that students can communicate with each other in the process of seeking common ground while reserving differences. So as to better cultivate the profundity of students' thinking and improve their discriminating ability.
Through review, students can deepen their understanding, consolidate their understanding and reduce their forgetfulness. Thinking from the law of students' acceptance of knowledge, the process of students' understanding of knowledge can not be achieved overnight, but starts from the initial perception, cognition, understanding, consolidation and improvement, and it should be copied and strengthened continuously, and this process of continuous copying and strengthening can be interspersed with the establishment of links between knowledge.
(C) Carefully designed examples
1. Grasp the key points and choose examples.
Due to the limitation of space, and in order to reflect the flexibility and optimization of review methods, the textbook adopts various presentation forms to give the knowledge points of review. Such as: think, say, do, please answer yourself, knowledge structure diagram. Form format, questions, questions, "ask more questions, be changeable and have more solutions". The problem group can directly give the meaning of the concept and review examples, and can also reflect on the thinking process, adapt the application questions, fill in the conditions, ask questions, adopt discussions and so on. Guide students to actively participate in review in various forms. When reviewing, teachers should focus on learning textbooks, pay attention to review strategies, select examples from exercises in a targeted manner, or design and supplement some representative and typical examples for effective review.
2. The sample design should reflect the following points:
(1) Example design should be conducive to mastering basic knowledge. There are many knowledge points in primary school mathematics, and the basic concepts, laws, properties and formulas are scattered in various chapters. When reviewing examples, we must carefully design examples around and including these knowledge points, so that the number is small, the coverage is wide and the inspiration is strong, otherwise we will lose sight of one thing and lose sight of another. For example, there are 90 longan trees and 270 litchi trees in the orchard. How many longan trees and litchi trees are there? After the answer, let the students ask other questions according to the two conditions in the question and make them into application questions. According to the conditions, it can be put forward: the sum of two numbers, the difference between two numbers, multiples, fractions, etc.
(2) The design of examples should be conducive to the change of topics and deepen the understanding of knowledge. For example, the key to reviewing "Elementary Arithmetic with Parentheses" is to understand the function of parentheses. For this reason, we can practice parenthesis to say the variation of operation order.
(3) Example design should be conducive to the comparison of knowledge. Review teaching, only through the comparison between before and after knowledge and between adjacent knowledge, can guide students to deepen their understanding of each part of knowledge and make students have a complete structure. Therefore, the comparison of knowledge should be taken into account when reviewing examples, so as to achieve the effect of giving inferences by analogy.
(4) Ingeniously guide refining and comprehensively improve.
Organizing effective exercises is an important means for students to master knowledge, form skills and develop intelligence. It is also an important part of review. It is particularly important that teachers should create problem situations according to the review content, and skillfully guide students to actively participate in the review process. Teachers should choose or design some exercise questions in a planned and targeted manner, so that students can be concise and concise, teach students in accordance with their aptitude in guidance and practice, and ensure that all students can be improved on the original basis. When designing exercises; Note the following points.
1. Focus on the basics. In the review, we should grasp the key points and carry out basic exercises. When reviewing scores, you can show the following exercises. ① 。
② Hours = () minutes, and kilograms = () grams. (3) A rope is 2 meters long and cut into 3 sections on average. Each section belongs to this rope, and each section is () meters long, which is 1 meter. ④3 km is 7 km, 2 1 km is (), and 2 1 km is () km. ⑤ When a= (), it is the maximum true score; When a= (), it is a false score; When a= (), it is equal to1; When a= (), it is equal to 0; When a = (), it is the decimal unit of this fraction.
2. Strengthen the system. In order to help students clear up their knowledge system and problem-solving ideas in review, typical exercises should be designed according to the requirements of review content, so as to achieve the purpose of systematic arrangement. For example, the refrigerator factory 5438+ 10 planned to produce 2800 boxes of refrigerators in June, but in fact it completed 55% of the planned output in the first half and 60% in the second half. How many refrigerators were actually produced than planned? (1) How many units completed the plan in the first half of the month? ② How many units were completed in the second half of the month? ③ How many units were actually produced? (4) How many units are actually added than planned?
3. Highlight pertinence. In the review, we should design comparative exercises for the weak links of mastering knowledge and some easily confused and error-prone knowledge, so that students can identify and master knowledge in comparison. For example, some confusing concepts in "Divisibility of Numbers", rewriting and ellipsis of numbers, perimeter and area, time and moment, volume and volume, ratio and proportion, the meaning of positive and negative proportion, etc.
4. Emphasize comprehensiveness. The ultimate goal of review is to improve students' ability to solve problems flexibly by using knowledge and methods comprehensively. Therefore, it is necessary to have a certain number of basic exercises and slightly changed exercises, as well as some comprehensive exercises and ideological exercises, so as to be hierarchical, gradient and flexible and meet the needs of students at different levels. For example: ① 6 ÷ 12 = 3: () = () Decimal = ()% = () Cheng. This problem relates the relationship between fraction, division and ratio, the relationship between fraction, decimal, percentage and number, and the basic properties of fraction in sequence. (2) First, cut the cube with the volume of 1 m3 into cubes with the average side length of 1 cm. Then put these small cubes together to make a cuboid with the length and width of 1 cm, so the length of this cuboid is () meters.
5. Reflect flexibility. The flexibility of thinking reflects the flexibility of thinking activities in choosing angles, using methods and developing process. In the review, some exercises are designed to use knowledge and methods flexibly, so that students can analyze and think about problems from different angles, broaden the thinking of solving problems and cultivate the flexibility and originality of thinking.
In the review class, teachers should first pay attention to it ideologically, and then adopt various review methods according to the characteristics of the textbook content to make the review class lively, constantly stimulate students' interest and improve the review efficiency. In this year's sixth grade graduation exam, the pass rate of our class was 100%, the average score was 89, and the excellent rate was 72%. Practice has proved that improving students' review interest can further develop their thinking flexibility and improve their ability to solve simple practical problems by comprehensively applying knowledge.