I. Talking about teaching materials
"Garbage Disposal" is the second lesson in Unit 4 of the sixth grade science textbook (Science and Education Edition). This is a science lesson closely related to our primary school students' daily life, mainly to let them know what garbage is in life, what kinds of garbage can be divided into, how to deal with it after classification, and how to reduce the discharge and pollution of garbage as much as possible. Let primary school students understand that the little environmental guardian has meaning from me. According to the existing cognitive rules and new curriculum ideas of sixth-grade students, this paper puts forward the learning purpose of "education should be oriented to all students, and students should learn to be independent, cooperative and inquiry in a relaxed learning atmosphere". I set the following teaching objectives:
1, let the students contact their real life and talk about what rubbish you see in your life.
2. Students write down your life style of garbage disposal through investigation and discussion.
3 emotional attitude goals; Ask the students to summarize the classification of garbage and talk about how to reduce the pollution of garbage as much as possible, improve the awareness of environmental protection and develop environmental habits.
4. preset goal: let students know the harm of garbage to us.
Teaching emphasis: cultivate students' ability to collect, analyze and process information, and arouse students' attention to things around them. Teaching difficulty: how to deal with garbage?
Teaching AIDS: multimedia courseware, mineral water bottle, a transparent cup, half a cup of pebbles, half a cup of washed fine sand, two paper balls soaked in ink, etc.
Two. Speaking and teaching methods
1. Stimulating interest introduction method
In this practical activity, I only play the role of organizer and guide, and try my best to let students actively participate in practice and explore independently. According to children's cognitive rules and the characteristics of teaching materials, I reproduce the situation with multimedia pictures and describe the multimedia situation with language to stimulate students' interest in learning and achieve the purpose of learning.
2. Experimental method
The new curriculum standard clearly points out that comprehensive practical activities should attach importance to students' personal views and behaviors, and emphasize students' self-help, independent choice and independent completion. Therefore, our teachers should return most of the classroom space to students as much as possible, so that students can give full play to the spirit of autonomy, cooperation and inquiry. Teachers only act as guides and promoters. According to the teaching idea of comprehensive practice, I adopt this teaching method in teaching, mainly to let students practice in a relaxed and pleasant atmosphere and gain knowledge and experience.
Three. Methods of speaking and learning
1, hands-on practice, independent exploration
The new curriculum standard advocates that "students are the main body of learning and development, and we should advocate independent, cooperative and inquiry learning methods." So in this class, I ask students to investigate the garbage around them in advance and fill out the questionnaire. Through conclusion exchange and independent inquiry, students can find problems, solve problems and be small masters of learning.
2. Group cooperation
As the saying goes, "Two heads are better than one." Group cooperative learning is not only an important way for students to acquire knowledge, but also an important way for students to learn. Cooperative learning not only helps to promote students' learning and intellectual development, but also helps to form and cultivate team spirit and learn to communicate with Bill. In teaching, I try my best to give full play to students' team spirit, personally participate in practice, and draw my own investigation conclusions.
Step 4: Say the tutorial.
(1) Introduction: Students, let's enjoy a group of pictures together and see if you all recognize where they are. What's your first impression after reading it? Really beautiful! In recent years, our mountain city in northern Fujian has developed rapidly, and some places are really beautiful, but if:
1. Show some photos of garbage piled in the open air to guide the dialogue: Is it still beautiful now? (Not beautiful) Why? (Too much garbage) is all caused by garbage, but it's not the fault of garbage! What shall we do (take it away) (put it in the garbage collection station) This is an idea. Show it: garbage in the recycling bin. Just leave it there? (No) Why? What problems will it cause if it is piled in the open air? (Environmental pollution) Can you be more specific? (air pollution) (water pollution) (mosquito breeding causes diseases) (land pollution) What about the blackboard? How to deal with it? (Landfill) (Incineration) (Composting) Blackboard Book Can you introduce the method of landfill first? (Student introduction) Why do you want to do this? (air pollution, water pollution and land pollution have all been solved) blackboard writing: it seems that the purpose of this work is to reduce the pollution of garbage to the environment. Can simple landfill really solve these problems? Today we will learn about garbage disposal.
The blackboard says: garbage disposal
(2) Research on simple landfill.
1. Teacher's explanation: Let's use an experiment to study simple landfill first.
2. Instruct students to read the contents on page 72 of the textbook, and analyze the landfill simulation attempt:
(1) What simulation attempt is this?
(2) What does the tested department represent? Bottom water represents groundwater; Sand represents the land;
3. Students try to simulate, and pay attention to carefully observe and describe its phenomenon.
4. Presentation and communication: What phenomena have we seen? What do you mean (the paper towel dipped in ink oozes ink and the water at the bottom of the cup turns black)? (When it rains, the rain slowly seeps into the soil, the garbage inside is soaked by water, and the sewage slowly seeps into the ground, polluting the groundwater. ) If this is a real garbage disposal site, can it be done? (No) What risks will it bring to the surrounding situation? (Water pollution, land pollution, air pollution, the number has not decreased, will account for a large part. Although landfill has made me invisible and achieved the purpose of being invisible and superficial, can it really solve the problem of pollution? (No) indicates that improvement is needed. What aspects should we think about? The guide should isolate the garbage from the surrounding soil, air and groundwater.
(3) Explore landfill to reduce pollution
1, in order to effectively prevent pollution by garbage. Can we design a better landfill? (Let the students talk about it, such as adding protective pads, collecting gas and filtering, and collecting filtrate.)
2. Students think and put forward the first method to solve the problem: (guide to separate the garbage from the surrounding soil, air and groundwater)
3. Group design exams and record design points.
4, the statement for instructions to convey the design and evaluation of each group.
5. Look at the organization chart of the real landfill and analyze how it prevents garbage pollution.
6. Will such a landfill be safe forever? Can you grow crops and build houses on them? (If you build a house, the foundation is unstable; If planted, the soil may be toxic)
Show me the introduction: (picture of landfill) After landfill, parks and stadiums can be built on it, but they can't be used to build houses and grow crops. Let's study the method of incineration.
(4) Study on waste incineration.
Teacher: You put forward the method of "burning". Can you introduce the benefits of this method? Advantages: it occupies less land and can reduce the amount of garbage. According to statistics, the amount can be reduced by nearly 90%. Avoid garbage pollution of groundwater and generate a lot of heat that can be used for power generation. )
2. Are there any shortcomings? (Problem: If it costs a lot, it will leave a residue. If it is not well controlled, it will also produce a lot of poisons and cause secondary pollution. )
3. Show the data of waste incineration.
(5), class summary:
These garbage disposal methods all have their advantages, but there are still many problems. What is a more effective way to solve the garbage problem? This requires everyone to experiment and study together. This is really: the road is long, and I will go up and down for it!
Reflections on the teaching of garbage disposal
Usually in science class, students are always required to collect some relevant information and talk about it in class; Do an experiment according to the class content. The scene is lively and feels good. But with live ammunition today, I feel this lesson is very difficult. Because science is rigorous and can't come at will, we should follow the law of "generating problems-exploring solutions-generating problems again-exploring solutions again". Teaching this class is based on the investigation and statistics of the first class. Students realize that the amount of garbage produced every day is huge, so it is natural to consider the disposal of garbage. According to the knowledge, students also know that there are two ways of garbage disposal: landfill and incineration, but they know little about the impact of these two ways on the environment, which is the problem to be solved in this lesson. The teaching activities of this course, through simulation experiments and discussions, help students realize the many impacts of garbage disposal on the environment. But if there is no more intuitive information in teaching, it is difficult for students to leave a deep impression on the environmental pollution caused by garbage, which has become the focus and difficulty of this course.
It is not difficult to operate the landfill simulation experiment. Through the teacher's demonstration, students can clearly see the process that the water at the bottom of the bottle is polluted and discolored, and they can also understand what objects in nature each part of the simulation experiment represents. If this experiment is to have a good effect and a certain shock, the bottle used in the experiment should be large, and it is best to use a small fish tank, which has a certain visual impact and can greatly stimulate students' interest. Through the experiment, the students realized the environmental pollution caused by random landfill, so they improved all parts of the simulation experiment and designed a more scientific and reasonable landfill. All of them can analyze the right things, get to the point, and the methods they think of are also in line with the application in real life. On this basis, introduce the schematic diagram of "new landfill" to students to deepen their understanding and give them a sense of accomplishment. Then guide students to analyze other problems of landfill disposal, such as land occupation and slow decomposition speed.
According to the advantages and disadvantages of landfill, guide students to analyze the advantages and disadvantages of garbage incineration, and students can also analyze and summarize it well. There is no problem. In summing up the activities of this lesson, we should emphasize that "although landfill or incineration has its own advantages, it is not the best way to solve the garbage problem", which leads to thinking: looking for more effective ways to solve the garbage problem. Introduce the activity to the next lesson.
In the process of students' discussion and communication and students' thinking collision, the teaching task of this course has been successfully completed. There seems to be nothing wrong, but something is always missing. What is missing? What is lacking is more vivid and storytelling media materials, especially video materials! Students rarely have access to landfills and waste incineration plants in their daily lives. It's hard to impress people with just a few pictures. In addition, it is difficult for teachers to collect this information, and students don't know where to start collecting information about garbage. Therefore, as a front-line teacher, there is a great need for more wonderful video resources to supplement classroom teaching and improve classroom teaching efficiency. The last science class is really difficult, especially for part-time teachers, because there is too much knowledge in this subject. People's energy is always limited, and sometimes they want to do things well, but they always pay attention to one thing and lose another, which is not worth the candle. Looking forward to the arrival of full-time teachers!