Judges and teachers:
Hello everyone! I said that the content of the class is the standard experimental textbook of compulsory education curriculum published by People's Education Press, and the third section of chapter 7 of seventh grade mathematics (Volume II) is "the sum of the inner angles of polygons". Below, I will elaborate the teaching design of this lesson from the following aspects.
I. teaching material analysis
1, the position and function of teaching materials. As the third section of Chapter 7, this lesson plays a connecting role. In content, from the sum of the internal angles of triangle to the sum of the internal angles of polygon, the formula of the sum of internal angles is applied to plane mosaic, interlocking and progressive. This arrangement is easy to stimulate students' interest in learning and is very suitable for students' cognitive characteristics. Through the study of this lesson, cultivate students' ability of exploration and induction, and experience important thinking methods from simple to complex, from special to general, and transformation.
2. Teaching Emphasis and Difficulty Emphasis: Inner and Outer Angles of Polygons and Difficulty: Exploring how to transform polygons into triangles when the inner angles of polygons sum.
Second, the analysis of teaching objectives
1, knowledge and skills: master the sum of inner and outer angles of polygons, and further understand the mathematical thought of transformation.
2. Mathematical thinking: can feel the order of mathematical thinking process, develop reasoning and language expression ability, and experience the method of understanding problems from special to general.
3. Problem solving: Let students try to find solutions from different angles and solve problems effectively.
4. Emotional attitude: Let students experience the sense of accomplishment that the conjecture is confirmed, and feel the existence of mathematics in life when solving problems. Experiential mathematics is full of exploration and creation.
Thirdly, the analysis of teaching methods and learning methods
This lesson draws lessons from Dewey's theory of "learning by doing" and the idea of "liberating students' hands, brains and time" advocated by Mr. Ye Shengtao. I have determined the following teaching methods and learning methods:
1, the design of teaching method I adopted the inquiry teaching method. The whole process of inquiry learning is full of communication and interaction between teachers and students, which shows that teachers are organizers, guides and collaborators of teaching activities, and students are the main body of learning.
2. The activity is to use students' curiosity to set questions, organize lively, interactive and effective teaching activities, encourage students to actively participate and make bold guesses, so that students can understand and master the content of this lesson in independent exploration and cooperation.
3. Application of modern educational technology I use courseware to assist teaching and present problem scenarios in time to enrich students' perceptual knowledge, enhance intuitive effects and improve classroom efficiency.
Fourth, teaching program design.
1. The teaching of this section will be carried out according to the following six processes: creating situations, introducing new lessons, exploring new knowledge through cooperation and exchange, drawing conclusions through independent exploration, trying to practice and apply new knowledge, summarizing and forming a system, and subliming emotions through group competition.
2. Teaching process
Interactive Link Interactive Content Design Intention 1 Create a situation and introduce new courses.
(1) In a contest to answer the basic knowledge of mathematics, Teacher Wang asked a question: All the angles of a polygon add up to the sum of its outer angles, so how many polygons does this polygon have? Xiao Ming solved the problem in only a few seconds. Is it okay?
(2) (Demonstration teaching aid) Four quadrangles with the same size and shape can be spliced into a blank cardboard. Do you know why? Through today's study, we can understand the truth and lead to the topic.
In this way, from the beginning, students will ask questions with quizzes and demonstration experiments with teaching AIDS. Students can easily ask: How many polygons is this polygon? Four quadrangles with the same size and shape can be spliced into a blank cardboard. Why is this effect? Therefore, it can arouse students' interest and attention in learning and create appropriate teaching situations.
2 Cooperation and exchange, exploring new knowledge
(1) Question: What is the sum of the internal angles of a triangle? What is the sum of the external angles? What is the sum of the inner angles of a rectangle? What is the sum of the internal angles of a square?
(2) Question: What is the sum of the internal angles of any quadrilateral? How did you get it? How many ways can you find?
(3) Students think and discuss in groups, and teachers participate in activities in groups to guide and listen to students' communication.
(4) Students are divided into groups to choose representatives to show the exploration results of the group, and teachers and students should judge together, and the different methods discovered by students should be affirmed in time.
Students may find the following methods:
(1) "quantity"-that is, first measure the degrees of the four internal angles of the quadrilateral, and then find the sum of the four internal angles;
(2) "Splicing"-that is, cutting off the four internal corners of the quadrilateral and splicing them together to get a rounded corner;
③ "Divide"-that is, divide the quadrilateral into triangles by adding auxiliary lines.
After the students show, the teacher asks:
① Among the methods of "quantity", "spelling" and "division", which method is simple and relatively accurate?
(2) We have just found several different auxiliary lines. What are their similarities?
Review the sum of the internal angles of triangles, squares and rectangles, and urge students to think and guess new problems.
Starting with a simple quadrilateral, it is easy to arouse students' interest in learning, encourage students to find a variety of methods, let students experience a variety of segmentation forms, help students deeply understand the essence of transformation-quadrilateral to triangle, and also let students experience the diversity of exploration and problem-solving methods in mathematical activities. Through communication, students can clearly express the process of solving problems in their own language, which can improve their language expression ability.
3 independent investigation concluded that
(1) Question: Can you calculate the sum of internal angles of pentagons, hexagons and heptagons by a similar method just now?
Students think independently, discuss in groups, and then describe the conclusion.
(2) Question: By analogy, what is the sum of the internal angles of the N-polygon? Let the students sum up by themselves, and get the formula of the sum of the inner angles of the N-polygon as (n-2) 180. From exploring the sum of internal angles of quadrilateral to pentagon, hexagon, heptagon and even N-polygon, by enhancing the complexity of graphics, students can experience the thinking method from simple to complex and from special to general, experience the transformation process again and feel the importance of cooperation in group communication.
Try to practice with new knowledge.
(1) Think about it: If one set of diagonals of a quadrilateral is complementary, what does the other set of diagonals matter? Why (for example on page 88 of the textbook 1).
(2) calculate it.
① Exercise 1 and 2 on page 89 of the textbook.
(2) what is the sum of the external angles of the quadrilateral?
③ What about the sum of the external angles of pentagon, hexagon and N-polygon?
(3) Read first, let the students read the last two paragraphs on page 89 of the textbook, and then I will show them with courseware. Consolidate new knowledge by doing examples and exercises. Find the sum of the external angles of quadrilateral first, and then find the sum of the external angles of pentagon, hexagon and n-polygon. I put forward a step-by-step question, so that students can gradually draw the conclusion that the sum of the outer angles of a polygon is equal to 360. These two paragraphs are newly added contents, which increase the understanding and knowledge of the external angles of arbitrary polygons from another angle. This not only pays attention to the reading and learning of teaching materials, but also demonstrates with courseware more vividly and intuitively, which is easy to understand.
5 summarize and form a system. I guide students to summarize from the following aspects:
(1) Now, can you answer the questions raised by Mr. Wang in the math knowledge contest? Do you know why four quadrangles with the same size and shape can be used to make a blank cardboard?
(2) What knowledge and methods have we learned in this class? What did you get? Let students use what they have learned to solve problems in questioning, improve their ability to solve problems, and encourage students to sum up the gains and experiences of this lesson freely, which is conducive to cultivating the habit and ability of summing up and allowing students to construct their own knowledge system.
6 group stage sublimates emotion
I made four different groups of electronic test papers, A, B, C and D, so that students can use what they have learned and cooperate in the form of group competition to master the situation by themselves. Through the way of competition, stimulate students' interest in learning, and guide students to consolidate knowledge and acquire skills through group cooperation in the process of doing problems.
Most of the papers in each group are selected from the exercises in the textbook. In addition, I also added 1 thinking question, which is actually a supplement to the method of proving the inner corner of quadrilateral, mainly to improve the flexibility of thinking by solving divergent thinking through one question, but also to review old knowledge, grasp the relationship between knowledge and let students experience the transformed thinking method again.
Evaluation and analysis of verbs (abbreviation of verb)
1. Pay attention to the diversification of evaluation contents. Through classroom activities such as students showing their understanding of what they have learned, exchanging views on a certain question, performing by hands, and trying to answer various questions, teachers can understand students from many aspects, such as students' thinking activities, their understanding and mastery of relevant content, and the procedures for students to participate in activities.
2. Pay attention to the evaluation of students' learning process. In the whole teaching process, students' ability to find problems is evaluated through their participation in mathematical activities, self-confidence, awareness of cooperation and communication, and habit of independent thinking, and the unique ideas or conclusions that appear among students are encouraged to be evaluated.
Design description of intransitive verbs
1, guiding ideology According to the requirements of mathematics curriculum in compulsory education stage, combined with the writing intention of teaching materials, when designing this lesson, I followed the following principles: introducing situations to stimulate interest, reflecting autonomy in the learning process, building knowledge step by step, and organically infiltrating thinking methods.
2. When dealing with the design of this lesson plan, I made the following changes to the textbook:
① Take the textbook example 1 as "think about it" in the exercise, and let the students try to answer it themselves;
② In Example 2, the sum of the external angles of a hexagon is changed to "calculation" in the exercise, so that students can find the sum of the external angles of a quadrilateral first, and then explore the sum of the external angles of pentagons, hexagons and n-polygons. This kind of treatment is still to reflect students' independent exploration and make students' learning change from "passive" to "active"
(3) The homework is completed in the form of group competition. In this way, emotionally, the students in this class have a strong enthusiasm for learning, from curiosity to doubt, from solving a single problem to feeling great excitement in solving the whole problem string. At this time, effective teaching competition can release students' passion for learning, make the subject personality manifest, and teachers can add a little bit, enough is enough, leaving more room for students to think. The above is my design description of this class. Please correct me if there are any shortcomings. Thank you!