First of all, talk about textbooks.
1. teaching material analysis.
The section "Solving problems by division", that is, teaching how to solve the practical problem that "one number is several times of another number" by division, is arranged in the textbook after the quotient is obtained by using the multiplication formula of 7 ~ 9. I think the reason why editors arrange this arrangement is not only to deepen students' understanding of the meaning of division, but also to have more opportunities to practice division calculation. More importantly, it can help students understand the connection between division calculation and real life and cultivate their awareness of applying mathematics.
In order to let students better understand the multiple relationship between two quantities and solve the practical problem of "how many times is one number another", the textbook also follows the principle of arrangement from shallow to deep. The logical sequence is as follows:
Example 2: Through the operation of swinging plane model, let students understand the meaning of "one number is several times that of another number".
Example 3, guide students to analyze and reason according to the concept of multiple and the meaning of division, and explore the general solution of "how many times is one number another".
The examples arranged in this way show students a logical picture from shallow to deep, from simple to complex, from intuitive operation to analytical reasoning. It follows students' cognitive rules, and in order to guide students to think methodically in the process of solving problems, it designs a step up.
2. Teaching content of this course: the content of pages 54 ~ 55 of the second volume of the compulsory education curriculum standard experimental textbook "Mathematics" published by People's Education Press.
3. Preparation of teaching AIDS: courseware, sticks, etc.
4. Teaching objectives.
The determination of the teaching objectives of this course embodies the concept of "development-oriented" as far as possible, paying attention to the implementation of "two basics" and the learning process of students. Therefore, the teaching objectives of this course are considered from three aspects: knowledge, ability and emotion.
(1) Through practical activities, let students understand the meaning of "one number is several times that of another number" and realize the relationship between quantities.
(2) Make students experience the process of transforming the practical problem "how many times is one number" into the mathematical problem "how many other numbers are included in one number", and initially learn how to solve simple practical problems by transformation.
(3) Cultivate students' cooperative consciousness and improve their inquiry ability.
5. Teaching focuses on difficulties.
Key points: Let students experience the process of abstracting the quantitative relationship of "one number is several times of another number" from practical problems, and solve practical problems with the technique of multiplication formula.
Difficulties: The quantitative relationship of "how many times one number is another number" is transformed into "the division meaning of several other numbers contained in one number" by using analytical reasoning.
Second, oral teaching methods
According to the above analysis, I adopt Ding's "independent inquiry teaching method" in teaching. Through audio-visual teaching, physical operation, cooperative communication and other teaching methods, a certain learning situation and a harmonious and democratic learning atmosphere are created, so that students can experience the teaching process of abstracting a specific problem into a mathematical problem and the process of determining the meaning of division when students solve the practical problem of "how many times is one number another". Take a variety of teaching methods, so that students can initially understand how to think about problems, how to use mathematical methods to deal with relevant information and solve problems reasonably.
Third, theoretical study.
1. Let students realize that there are multiple relationships among many quantities in life through operational activities.
2. Use independent thinking and cooperative communication to guide students to express their thinking process in concise language.
Fourth, talk about the teaching process
The teaching of this course is completely based on the arrangement idea of teaching materials and explores the arrangement characteristics of teaching materials. The teaching is divided into the following links.
(A) contact with reality, review the old knowledge
Taking the number of times students in this class take part in extracurricular activities as an example, I designed three review questions to find out how many times a number is. For example, the question 1: There are three students studying dance in Class 3, Grade 2, and the students studying painting are twice as many as those studying dance. How many people are learning to draw? After the students say the answers, talk about the thinking process. At this time, the teacher asked six students who studied painting to wave to everyone and then report their academic performance. The teacher congratulated the students who got excellent grades.
The design intent of the review meeting is threefold. First, arouse students' memory of existing knowledge and make intellectual and psychological preparations for learning new knowledge. The other is to keep close contact with students' real life when reviewing, so that teachers and students can blend their feelings and have a happy learning mood. The third is to create a situation, so that students can observe and analyze daily life problems from a mathematical perspective and stimulate students' desire for learning.
(2) Hands-on operation to explore new knowledge.
In the new teaching part of the class, I designed a game activity combined with the audio-visual teaching of Example 2, so that students can build a plane with sticks to participate. The main process is as follows: First, show the theme map of Example 2 on 54 pages in the form of animation (three students are posing the plane with sticks) to demonstrate the process of posing the plane with five sticks. Then the teacher asked, "Do you want to take part in this game?" Guide students to participate in the activities of flying by hand. After the students set up the plane, they reported the results with music, such as "I set up a plane with five sticks" and "I set up three planes with 15 sticks" and so on. On this basis, the teacher asked "according to the plane you placed, who can ask a question for everyone to guess?" The students are full of enthusiasm. They ask questions such as "I built several planes with the stick of 10", which leads to "Find the division meaning of several other numbers in one number", laying a foundation for learning "One number is several times that of another number". On the basis of students' hands-on operation and eye movement observation, the courseware shows Xiao Qiang's question in the example: "How many times did I use the stick when I set three planes?" How to solve this problem? I asked my classmates to discuss in a group and found out, "How many times is one number the other?" That is to say, "how many times is one number more than another", that is, "how many other numbers does a number contain?" Divided by, 15 ÷ 5 = 3. In such teaching activities, students have experienced the process of solving problems, learned to observe and analyze practical problems with mathematical thinking, learned to ask, understand and solve problems with mathematical point of view, and cultivated the ability to solve practical problems by comprehensively applying what they have learned.
(C) the use of knowledge to solve problems
Due to the review of the concept of multiple and the study of Example 2, students have understood the idea of solving the problem of "how many times is one number another" by division calculation, so in this link, I completely let students ask their own questions and solve their own problems. At the beginning, the courseware showed, for example, 3: 35 people were singing, 7 people were dancing and 5 people were watching the program. Ask the students to ask questions about division calculation according to the pictures, such as "How many times do you sing and dance?" "How many times do you sing than watch programs?" By analogy, according to the questions raised, the group will discuss the solutions. After the students solve the problems independently, they will explain the ideas of the problems, so that students can not only master the knowledge more firmly, but also appreciate the gains brought by cooperation and exchange.
The teaching design of this link abandons the routine of analyzing the quantitative relationship and finding solutions in the traditional application problem teaching process, and combines the application problem with the operation teaching, focusing on guiding students to solve problems. Because the purpose of students' learning is not to get the correct answer quickly, but to focus on exploration and research activities and seek creative solutions in the process of solving problems.
(4) Consolidate and deepen, and question and expand.
In this link, I designed various forms of exercises, including basic exercises, variant exercises and open exercises, with the aim of consolidating new knowledge, helping students to further clarify their problem-solving ideas and achieve mastery.
(v) Development evaluation
Let students talk about their performance and gains in this class, which embodies the new curriculum concept and gives students the opportunity to fully express themselves.