The teaching goal of this course is to let students explore and discover the arrangement law of simple periodic phenomena in combination with specific conditions, and determine the object or figure represented by a certain serial number according to the law. The key and difficult point in teaching is to guide students to master the method of division calculation step by step to solve problems. In order to achieve teaching objectives and breakthroughs in key and difficult points, I designed five links for this course. The design of each link fully considers the students' cognitive level and learning state, and the links are closely connected and the transition is natural.
Pre-class game: Happy clapping game. Reflection: A few minutes before class, sharing regular and rhythmic clapping games with students can not only relax students' body and mind, relieve their learning pressure, but also understand the rules in the game. Warm up for this class.
The first link, start thinking, the game is introduced: memory game.
Teacher: Students, the teacher has always had a question, which of the boys and girls in our class has a good memory? What did you say?/Sorry? This suspicion immediately triggered the contradiction between boys and girls!
At this time, the teacher can play the role of referee and provoke a memory contest between boys and girls.
Female students chose the red number string, while male students chose the black number string. In ten seconds, see who can remember the number string.
Red:1386138613861386 ... black:1392810138644275 ...
The game is naturally won by female students! The teacher announced: Female students have a good memory! At this time, male students naturally do not admit defeat! At this time, the teacher asked the male students why they were not convinced. Boy (indignant): The red number string is regular! This game is unfair!
Introduction: Find the law (blackboard writing)
Reflection: In this link, the game stimulates classroom conflicts, and the teacher leads to the topic conveniently, which not only "hangs" the students' appetite for knowledge, but also leads to the example of 1 for the teacher, naturally!
The second part, the simple mathematical concept and rule of thumb of spinning.
1, Teacher:1386138613861386 What are the rules? Teachers pay attention to students' answers, such as "1386 1386 is repetitive"; "1386 1386 is arranged in numerical order", which will be affirmed and praised in time! The mathematical concepts such as periodicity and arrangement are gradually extended. Teacher: Can you list some such laws?
2. Courseware shows the arrangement law of periodic phenomena in life and realizes that mathematics comes from life.
Reflection: Find examples in life and experience laws in life examples, so that students can realize that mathematics comes from life and accept these abstract mathematical concepts simply and naturally.
The third ring, thinking begins, preparing for action and exploring new knowledge.
Teacher: The students just said that the memory game is unfair, so now let's play a fair game. Look at the boys and girls, who is quick! Divisions organize queuing games.
1, queuing games: men and women, men and women. ...
Teacher: It seems that in the case of fair play, the reaction ability of boys and girls is neck and neck, equally divided! What rules have you found in this game? Health report.
Let me see the question: So, from the left, is 15 a boy or a girl? Group discussion and communication methods.
2, the student report method:
Student 1: I draw. Student 2: I use enumeration method. Singular numbers represent male students and even numbers represent female students.
The calculation method I use is: 15÷2=7 (group) ... 1 (group).
3. The teacher asked: What is the dividend 15 here? How is the divisor 2 determined? What is quotient 7? What about the rest 1?
Students discuss and report, and teachers guide students to summarize methods.
4. Teacher: When solving this problem, the students all have their own methods, which are very good, but which one do you think is easier? Organize students to compare methods. Students can quickly tell whether 17, 3 1, 58, 153 from the left are male or female through enumeration. By comparison, students find it easier to enumerate, and they are convinced of their own judgment! At this time, the teacher asked: can all the problems of finding patterns be solved by enumeration? Students fall into thinking, which naturally leads to "star queuing".
Reflection: The introduction of queuing games makes students feel the rules in the game and have a strong thirst for knowledge. This link makes students' thinking "blocked". Teachers only need to guide students to gently step on the "accelerator" and students will "move"! The conversion between Example 1 and Example 2 is natural! This link enables students to actively experience the process of independent exploration, cooperation and communication, experience the process of drawing, enumerating and calculating different problem-solving strategies, and gradually optimize methods.
The fourth ring, easy to "shift gears", full of power, internalizing new knowledge.
1, star queue: Liu Xing Xiaoxue, Liu Xing Xiaoxue Question: If this continues, who is the 23rd from the left?
Teacher: Can I still enumerate at this time? Students discuss what strategies to use and complete the report:
23÷3 =7 (group) ... 2. Name (individual) explaining the meaning of the formula.
2. Compare the results. * * * Summary of teachers and students: When solving the law of periodic phenomena, the calculation method can be used.
3. Solve the problem by calculation, and the students finish and report.
Reflection: In this part, the content form has been modified without violating the objectives and intentions of the textbook, making the content more vivid and more in line with the reality of their own students. Their favorite TV characters took over the previous part, "Can all the laws of periodic phenomena be solved by enumeration?" This problem arises at the historic moment. In fact, students can overturn previous guesses through their own thinking! It embodies the rational cognitive process of contradiction generation and resolution in the development of thinking. Everything is so natural.
The fifth ring is smooth and handy.
In this section, we designed "Smart and Brave" to consolidate and expand the knowledge of this lesson. Including the consolidation of the understanding of the law, the investigation of using calculation methods to solve the problems of the law, the flexible application on the basis of mastering the use of calculation methods to solve problems, the further development of thinking ability, the stimulation of students' desire to challenge themselves, the further improvement of students' thinking ability and successful experience.
The sixth ring, sublimation and crystallization, class summary
Reflection after class
Classroom teaching is still the main channel to develop students' brains and thinking, and teachers are still the guides and guides in the classroom. Therefore, it is an important prerequisite for us to cultivate students' mathematical thinking to change teachers' ideas and dig deep into the relevant factors in mathematics textbooks. To regard students' thinking as an engine, how to start it and how to make it work well mainly depends on how the classroom instructor controls it! This requires teachers to carefully consider all aspects of classroom teaching, and design all aspects reasonably and scientifically according to the classroom situation and students' cognitive level, so as to be interlocking and not out of touch. Students' potential thinking is stimulated step by step and guided step by step, forming a cognitive process of new knowledge from perceptual to rational.
blackboard-writing design