"How does the sound come into being" is the content of the second lesson of "Sound" in Unit 1 of the fourth grade of science in the standard experimental textbook of compulsory education curriculum. It belongs to the target series of "scientific inquiry". Through experiments and observation, we know that sound is produced by the vibration of objects, which cultivates students' experimental observation ability, analysis and generalization ability and innovation ability. This lesson plays a connecting role in this unit. Based on the previous section "Listening to sound", it studies and explores "How sound is produced", and makes full knowledge preparation for the following exploration activities such as "How sound spreads" and "Controlling objects to make sounds".

Analysis of learning situation Before studying this lesson, as a fourth-grade student, I had a rich intuitive feeling about the sound phenomenon in the sound life. However, familiar phenomena do not necessarily lead to students' independent inquiry thinking, which is the value of our teaching. Based on this idea, teachers can collect audio recordings of sounds before class. At the beginning of the class, I will make a fuss about the word "familiarity" and let students play the game of "guessing objects by listening to sounds" and introduce it into this class. In line with the age characteristics of students, let students feel that they live in an environment full of sound, and stimulate students' interest in learning more about sound secrets.

Second, talk about teaching methods and learning methods around the goal.

1, knowledge and ability goal: know that sound is produced by object vibration;

2. Process and method: We can observe, compare and describe different phenomena of objects with and without sound; Can explain the reason hypothetically from the observation facts of multiple objects sounding; You can use other objects to observe phenomena that are not easy to observe;

3. Emotion, attitude and values: in the process of inquiry, actively and boldly expound your findings; Willing to cooperate with others, develop the habit and attitude of careful observation. The focus of teaching is to cultivate students' ability to observe experiments, analyze and summarize and innovate by understanding that sound is the process of object vibration;

Teaching difficulties in understanding the relationship between sound generation and object vibration.

Teaching preparation:

The teacher prepares drums, tuning forks, water tanks and courseware.

Students prepare in groups: drums, beans, steel rulers, rubber bands and small wooden frames.

Teaching methods and learning methods

1, teaching methods

Situational interest stimulation method: Introduce the game of "guessing objects by listening to sounds" into this lesson to stimulate students' interest in learning.

Multimedia-assisted method: Use multimedia courseware, sound files and picture files for intuitive demonstration, integrate science teaching with information technology, and inspire students to actively explore the generation of sound.

Step-by-step method: According to the cognitive level of fourth-grade students, exploratory experiments are not suitable for striding teaching, so it is advisable to design teaching in a step-by-step way.

Experimental demonstration method: through experimental observation, we can understand that sound is produced by object vibration, and cultivate students' experimental observation ability, analysis and generalization ability and innovation ability.

Step 2 study law

(1) experimental inquiry method: let students explore the sound generation independently in the experiment and take the initiative to obtain information.

(2) Group cooperation method: in the form of group cooperation, we go deep into scientific inquiry activities and improve scientific literacy in the activities.

(3) Communication and discussion method: Let students fully communicate and discuss the nature of sound in the experiment.

Third, grasp the main line and talk about plates and links.

(1) Stimulate the introduction and reveal the topic.

A good beginning is half the battle. Proper lead-in can stimulate students' interest and create the best learning atmosphere for new class teaching. According to the psychological characteristics of primary school students' strong curiosity, at the beginning of class, I designed a game of "listening to sounds and guessing objects" to attract students' attention to sounds: "Students, the teacher brought you a special gift today. Please close your eyes and listen carefully. " (Play the sound) After listening, report the sound you hear: the sound of cars, trains, wind, thunder, rain, etc. Let students initially feel that we live in an environment full of sound, and stimulate students' interest in learning more about sound secrets. Then he said, "We live in a world full of sounds. What questions do you want to ask about sound? " . Students will definitely ask many questions: for example, how did the sound come from? How to control the sound and other issues. -thus revealing the topic of "how sound is produced".

(2) Group experiments and step-by-step guidance.

Activity 1: Make an object make a sound.

How to guide students to make guesses step by step through experiments and verify them step by step? I designed the following links.

(1) Define the objectives and requirements.

(2) Experiment in groups and complete the form.

(3) Feedback and communication, evaluation and guidance.

(4) Questioning leads to conflict.

(5) Observing the experiment and initially establishing the concept that "sound is produced by the vibration of objects".

In the first part, I will have the following dialogue with students: Students, next we will find the answer through experimental inquiry activities. The teacher prepared drums, steel rulers and rubber bands for each group. Can you find a way to make them make a sound? Let's do the experiment in groups. Before you do the experiment, please look at the purpose and requirements of the experiment. (Courseware demonstration)

After the students have made clear the purpose and requirements of the experiment, they will enter the second part of the activity. Students will experiment in groups, complete the form, and the teacher will patrol and guide. In this session, students may pay attention to the volume of the sound. At this time, I will remind the students: "The teacher is not looking at which group of students make sounds, but at which group of students think of many ways to make objects make sounds." This can not only manage the classroom, but also cultivate students' divergent thinking.

After the students fully operate and complete the form, they enter the link of "feedback and communication, evaluation and guidance". I put forward the core question to be discussed in this class: "How does the sound come into being?" At this time, the students' answers are based on their existing experience. Students' guess may be that "sound is produced by the action of force on objects" or "sound is produced by the movement of objects". Of course, these conjectures do not explore the nature of sound. But as long as it is based on what students think and see during the experiment, I will affirm it and let students evaluate each other. In this period of teaching, I am not in a hurry to instill the concept of "object vibration produces sound" into students, but through the next link of "asking questions", students' guesses and facts have a strong conflict, thus triggering students' desire for further exploration.

So in the fourth quarter, I will ask the students: "If the sound is produced by the force or movement of an object, as you guessed, why doesn't the object make a sound when it is stressed, bent or stretched?" This question will shake the students' previous guess. When the students were at a loss, the teacher threw out a new task: "Do the experiment just now and observe carefully: what are the common characteristics of different objects when they make sounds."

Students do the experiment again. After observing the experiment, communicate and report. Most students may find that "rulers and rubber bands move when they make a sound", and they may say that they are vibrating. At this time, I will tell the students that the word "vibration" is more accurate and write the word "vibration" on the blackboard. (Blackboard book vibrates)

Later, I further asked: We saw the ruler and rubber band vibrating through experiments, so is the sound made by the drum vibrating? Can you find a way to see if the drum surface vibrates? Students can put forward methods such as touching by hand, and teachers can guide students to borrow beans to observe whether the drum surface is vibrating when the drum sounds. When the students see the beans beating on the drum surface of the sounding drum, the teacher strikes while the iron is hot, and transitions to the third part of the teaching process-observing the experiment in the form of questions to form concepts.

(3) Observe the experiment and form the concept.

Activity 2: Observe the sounding object.

1. The teacher shows the tuning fork and taps it. Ask the students: The tuning fork makes sound after being struck. Can you find a way to show your eyes if the tuning fork is vibrating? When listening to students' methods, guide students to borrow water to observe in time-put the vibrating tuning fork into the water and observe what happens on the water surface to judge whether the tuning fork is vibrating.

2. Let the students talk freely about their observed phenomena, and the teacher sums it up in time: when an object (such as a tuning fork, drum, steel rule, rubber band, nail, etc. ) it can do reciprocating motion repeatedly under the action of force, and it is a vibrating object. Then guide students to sum up the concept of "objects vibrate to produce sound", and teachers can improve blackboard writing.

In order to strengthen students' understanding of this concept, I designed an interesting experiment: how to make the drums disappear immediately? The students found through experiments that when the vibration of the drum stopped, the sound disappeared. At this point, students have recognized and understood the scientific concept of "objects vibrate to produce sound".

(D) Expand doubts and pave the way for the follow-up research.

"Musicians can use the vibration of strings to deduce many beautiful songs. Please listen! " (Courseware plays music), after listening, we ask: After listening to this piece of music just now, is there anything you want to know about sound? Students may ask, "How does sound make us hear?" "Why is the sound high and low?" At this time, I will tell the students that these questions are what they will learn step by step, so that the instructor can find the answers by himself through various channels first, so as to discuss them with teachers and classmates in the later study. Finally, I end this lesson with this sentence: There are still many mysteries about sound waiting for us to explore. Let's look forward to the next science class!

Fourth, stick to the theme, write on the blackboard and summarize.

How is sound produced?

Objects vibrate to produce sound.

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The above is my understanding and teaching analysis of the textbook How Sound is Generated. In the whole teaching process, I always strive to implement the guiding ideology of teacher-centered, student-centered, problem-based and ability-oriented, and cultivate students' experimental observation ability, analysis and generalization ability and innovation ability in a planned way. And use a variety of teaching methods to stimulate students' interest in learning and enthusiasm for inquiry, so that students can gradually deepen their inquiry activities, acquire scientific knowledge and learn scientific inquiry methods, and cultivate students' scientific literacy.