[Teaching objectives]
1. Through observation, guessing, hands-on operation, cooperation and communication and other situational activities, students can initially master the methods and strategies of orderly collocation in specific life situations.
2. Combining with the reality of life, cultivate students' ability to think in an orderly way, make students develop the habit of thinking in an all-round way, not repeating or omitting, cultivate students' awareness of solving mathematical problems in life, stimulate students' desire to explore mathematical problems in life, and cultivate students' interest in learning mathematics.
[teaching material analysis]
Design intent
The textbooks in this section provide students with realistic, interesting and challenging learning materials. The textbook provides three menus on Monday, Wednesday and Friday, and each menu has several meat dishes and vegetarian dishes. If you mix them with meat and vegetables, how many different side dishes will you have? To solve these problems, students can gradually explore different methods according to their own experience and finally find the law of collocation. At the same time, students can accumulate experience and strategies to solve problems through this section.
Design concept
According to the requirements of the Standard, the teaching of this course should be closely linked with students' real life. Based on students' life experience and existing knowledge, design vivid, interesting and intuitive mathematics teaching situations to guide students to seek solutions to problems through observation, questioning, reasoning, performance and communication, and learn to transfer and use.
Problems that should be paid attention to in teaching: encourage each student to participate in the learning process, pay attention to the communication between students, and make students inspire and improve each other; Let students experience and understand the collocation method, apply what they have learned to their lives, solve the mathematical problems around them, and realize the importance of learning mathematics.
Analysis of the situation of schools and students
The third-grade pupils living in Zhongshan District, Dalian Economic and Cultural Development Experimental Zone, an open coastal city, have rich life experience, excellent living conditions and active thinking, and have the psychological characteristics of being active, curious and competitive.
[Instructional design]
(A) situational import
1. Introduction.
The annual Dalian International Fashion Festival was held as scheduled. Let's look at the latest report that the reporter just sent from the airport. Watch a TV video: show the scene where city leaders meet with the US delegation to shake hands and say hello, and stop at the scene where Mayor Xia Deren and Vice Mayor He shake hands with three representatives of the US respectively.
2. Question: What math problems can you find from it?
The student thought about it and asked: How much mineral water is there on the table in the living room? How many people attended the meeting? How many times did the mayor shake hands with the American representative? ..... (There are still some problems that are out of the research scope of mathematics class and deviate from the teaching objectives, but what they say is really what they see and think when they observe. If you want to get to the point, you need to take your time. )
Pay attention to the life situations that students are interested in, introduce new lessons through vivid materials in real life, make abstract mathematics knowledge have rich realistic background, strive to provide students with a lively learning environment, let students ask questions about mathematics themselves, and realize role transformation through mutual questions between teachers and students. )
3. Location of the problem.
Teacher: You really have a good eye for mathematics. Shaking hands is a kind of etiquette. In this etiquette, there is also mathematical knowledge to explore! Let's first study how many times our two mayors shook hands with three American representatives, shall we?
4. reveal the topic.
Teacher: Today we are going to study an interesting math problem-knowledge in collocation. (blackboard writing topic: knowledge in collocation)
Methodological and strategic guidance
1. Continue to play the video once, and let the students watch the video and play it back twice.
Let the students think independently, and then tell the thinking process. The students scrambled to say that the time had come, and I was glad. )
Health 1: one * * * holds 6 times, 3+3 = 6.
Sheng 2:1* * was held five times, and 2+3 = 5.
Sheng 3: 1 * * * held 6 times, 2× 3 = 6.
Teacher: How many times does Yi shake hands? Which group would like to come to the front and shake hands? Pay attention to shake hands to avoid repetition or omission. (Give timely praise to the group that is serious in performance, careful in observation and attentive in listening)
1 group, a group of five people, play the mayor, deputy mayor and three representatives of the United States respectively, experience the handshake scene and feel the collocation method in the activity.
In the second group, the activity was recorded by connection, and different handshake matching methods were obtained.
For 1, for 1.
On behalf of Mayor Xia, congratulations on behalf of Mayor Xia.
Represents 3 instead of 3.
Through role-playing, each group comes to the conclusion that students' answers 1 and 3 are correct.
At this level, students can think and explore ways to solve problems by themselves, and discover, experience and appreciate the process from abstract to concrete through role-playing, so that students can master the methods and come naturally. )
2. The teacher pointed out according to the situation: If China has Theory of Three Represents and the United States has five representatives, how many different ways are there to shake hands? Please think independently first, then cooperate with your classmates in the group to study, and then communicate and talk about the thinking process. After two minutes' research, the group reported that the students' emotions were mobilized. Some use symbols, some use words, some live demonstrations, and some draw charts. )
Group 1: 5+5 = 15 (times) with the help of the diagram above.
Group 2: Can you express it in your favorite way?
Teacher: Of course. The teacher helps to express the collocation process in letters in time and gives method guidance. )
On the premise of independent thinking, comment communication has a new generation, which is the real communication. )
The students said:
The United States represents the United States represents the United States represents the United States represents the United States represents the United States.
The United States stands for the United States, the United States stands for the United States.
China stands for A, the United States stands for C, China stands for B, the United States stands for C, China stands for C, the United States stands for C, China stands for C, and the United States stands for C.
America stands for America, America stands for America, America stands for America, and America stands for America.
America stands for America, America stands for America, America stands for America, and America stands for America.
The third group: connection mode.
Group 4: List formulas.
The fifth group: the collocation method of text narration.