1, know the distance, size and heat of the sun, know the close relationship between the sun and people, and stimulate students' enthusiasm for studying celestial bodies.
2. Cultivate students' methods and interests in reading expository texts.
3. Understand the function of related words such as "I feel … actually …" seems … actually … "If …" Although … but … ".
Preparation before class
When there is an annular eclipse, lead the students to observe it first, or put a slide show of the sun.
Class arrangement
The first lesson: introduce a new lesson, create a problem situation, teach yourself the text, divide it into sections and read the first paragraph.
The second class: read the second and third paragraphs and create situational consolidation exercises.
teaching process
first kind
First, lead-in (combining children's life to stimulate interest in learning new lessons).
Yesterday afternoon, for three hours, the students paid close attention to the changes of the sun. At the same time, hundreds of millions of eyes are watching the sun, observing and studying the strange phenomenon of annular eclipse. Judging from the enthusiasm of the students, everyone is quite interested in exploring the mysteries of celestial bodies.
In this class, students are invited to be small scientists and study the sun. (blackboard writing: the sun)
Second, create a situation to learn from the sun and encourage children to actively think about new lessons. (Showing the sun slide)
Using audio-visual education to create a situation: the rising sun is radiant and dazzling, and the electric light source that projects slides makes the picture realistic. At this time, the sun 30 million kilometers away from the earth suddenly pushed in front of the students. This vivid image, coupled with the child's strong thirst for knowledge, has entered the problem situation. )
1, inspiration: The sun that we can see every day rises in the east in the morning and brings light to the earth; In the evening, when the sky falls from the west, darkness falls. The sun seems familiar to us; It's actually very strange. Because we know very little about the real situation of the sun. It needs scientists of all ages to study it and uncover its mystery.
To study a thing, we must first ask questions. (blackboard writing: "?" Now that you face the sun, what do you want to know about it?
Students ask questions. It is estimated that students will ask questions about the size, distance, temperature and phenomenon of the sun. )
2. The teacher classifies and summarizes the students' problems.
Teacher's encouragement: These questions are very good, which shows that the students have a certain scientific spirit and attitude.
How do you find the answers to these questions? One is to find the answer from the text "The Sun", the other is to read relevant materials after class to learn more, and the third is that some of us humans have not reached a conclusion yet, and it is up to you to study, discover and answer.
Dealing with problems in this way not only makes students actively learn the text with great interest-this is the most important thing; It can also broaden students' thinking. It has played a very good guiding role. )
Third, teach yourself the text and find the answer. (further stimulate learning motivation and initially cultivate students' ability to consult materials and solve problems. )
The relationship between how far, how big and how hot the sun is and people is clearly stated in the article. Now we will read this text as material. Learning science requires asking questions and solving problems, which requires learning to consult materials and some experiments. Please read the information about the sun now. See who finds the answer through their own reading.
Invisibly, it brings students into the situation of learning science, searching and reading materials. They seem to be a little scientist. At this time, they were absorbed in reading the text. )
2. Students teach themselves.
△ Guidance ①.
For this kind of popular science exposition, one section generally explains one meaning, and the content of each section should be summarized first when reading.
(blackboard writing: one section and one meaning)
Ask students to write a summary of each section on each section when reading, just like taking notes.
△ Guidance ②.
After summarizing the contents of each section, it is necessary to further clarify that the full text can be divided into several parts.
Instruct students to communicate and fill in various types of sections:
Instruction: Read the explanatory text. First, distinguish levels and summarize paragraphs. (Blackboard symbol 〢〢)
In fact, this is a way to teach students to learn expository texts and read popular science books to find out the main meaning of each section and layer. )
Read the text again, check and report the answers in different forms.
Let students continue to play the role of small scientists, which will further bring students into the situation of studying the sun and deeply understanding the learning materials.
The first paragraph:
1. How far, how big and how hot is the sun? Can you little scientists find the answer by yourselves? (The students answer, and the teacher fills in the numbers in the table. See the table below)
2. Guidance: From this table, we can know what explains the distance, size and heat of the sun.
(blackboard writing: enumerating figures)
There are many figures in the data, which can be listed. Once you fill in the numbers, you can see them at a glance.
3. Is the article only explained by numbers? What else did you do?
4. Read the text by name and then answer.
(1) Reference Legend (blackboard writing: Reference Legend)
Who still remembers a story about the legend of the sun that we learned in the second grade? Who can tell me?
If there is no legend here, just numbers, these three paragraphs will become:
"The sun is far away from us, with 30,000 kilometers.
The sun is very big, which is 6.5438+0.3 million times that of the earth.
The sun is very hot, with a surface temperature of 6,000 degrees and a center temperature of180,000 degrees. "
What's your interest in reading this article?
(In this way, the teaching enriches the content of the text and closely follows the text, thus strengthening students' interest in learning. )
② Guidance: "Legend" is an oral story circulated among the people. Studying science is very scientific, and its essence must be explained. here
After the legend, what words are used to reveal the essence? The legend quoted in the article is fascinating, and then the word "actually" is used to reveal the essence.
(blackboard writing: explaining the essence of legend)
What words are used in the following section to illustrate the essence? (blackboard writing: I think it is actually)
(3) When it comes to the sun, why do you want to talk about the earth, boiled water and steel? (Highlight words such as "worth" and "ratio". (blackboard writing: comparison)
As the saying goes, "if you don't know the goods, you are afraid to shop around." Comparative method can help readers to further understand what is explained.
④ Guide students to think about the relationship between things. The three characteristics of the sun, namely "big", "hot" and "far", are all related to our earth.
Departments are interrelated. If you want to be a scientist, you must think carefully and think about some problems yourself when reading materials.
Example: (show sentence pattern: because ... therefore ...)
△ Although the sun is big, it looks small because it is far away.
△ Although the sun is hot, it can't burn life on the earth because it is far away.
△ Because the sun is big, the whole earth can be illuminated by the sun.
△ Because the sun is very hot and far away from us, it makes us feel warm.
Second lesson
The second paragraph:
1, put forward that the analysis at home is very good. Specifically, how close is the relationship between the sun and people? We should study this problem carefully. Now learn the second part of the text.
Read the second part by yourself and talk about how close the sun is to us according to your usual observation and the information provided in the book.
Provide sentence patterns: A. Being with the sun ...
If there is no sun ... then ... because ...
Show two sentence patterns, which students can choose at will to show that they teach students in accordance with their aptitude. )
3. After reading and discussing, students answer and practice saying the above sentences.
4. Guidance: This section first says "with the sun …" and then says "without the sun …" On the other hand, it shows a close relationship. From phenomenon to essence, use "as if … in fact …".
5. Question: What sentence is used to summarize the content of this section? The book summarizes this passage into one sentence: "Although the sun is so far away from us, it has a very close relationship with us." Written at the beginning of this paragraph, this is called "summary at the beginning of the paragraph" (blackboard writing: summary at the beginning of the paragraph)
When reading this kind of article, we should pay attention to the words at the beginning of the section, which can often help us grasp the content of the whole section.
The sun is far away from us, so it doesn't matter much. Here, the meaning has changed, so we use "although … but ……".
6. Read the whole paragraph. Read the first sentence together and read the following sentences in turn.
The third paragraph
The second paragraph talks about the relationship between the sun and us, so what is the relationship between the sun and nature? When we study, we can mark them with arrows and find out the relationship between them.
Show two groups of cards: 1. Solar water, rain, snow, water vapor, water drop clouds.
2. The sun has more heat and less hot and cold air.
Paragraph four.
Read by name. Read it together. (Highlight "None ... None ...")
Fifth, make a small exhibition of "Sun" and carry out consolidation exercises.
Stimulate interest and define needs.
1On September 23rd, 987, a rare annular solar eclipse was observed in China. In order to help students understand the sun, we little scientists held a small exhibition about the sun. The exhibition uses pictures, slides, animations and other forms to show and introduce the relationship between the sun and people, which is the main part of the exhibition. Now please play the role of Grandfather Sun in the animation, who was a child. Let's talk. Children ask questions, and Sun Gonggong answers, helping children understand Sun.
△ Same seat dialogue. (The whole class is generally role training)
△ Play the narration by name.
Animation performance
(At this time, the creation of the situation needs to be comprehensive. It is necessary not only to consolidate the knowledge learned in this lesson and deepen the impression, but also to use it flexibly and cultivate the ability. Create an "exhibition" situation to make students feel fresh and interesting, especially the role of cartoons, to make children interested.
Summary:
1. The study in this lesson makes us understand how far, how big and how hot the sun is. I know that the sun is closely related to people. Without the sun, there would be no animals, plants, humans, clouds, snow and frost, and there would be no such beautiful and lovely world.
Learning this article also lets us know how to read the explanatory text.
Generally speaking, the writing methods of expository articles are "one section with one meaning" and "paragraph summary", and the essence and causal relationship of things are often explained by "quoting legends", "enumerating data" and "comparing". Therefore, in reading, in view of these characteristics, we should summarize one section with one meaning, add interest by citing illustrations, draw tables by listing data, and grasp the essence and understand the cause and effect.
Students can pay attention to the astronomical phenomena, or study books and materials carefully and conduct research, just like young scientists.