Activity design background
On a sunny morning, the children were chasing the shadows of themselves and other children on the playground and had a good time. I went up to them and asked them, "What are you chasing?" The children replied, "Shadow." I asked again, "Do you know how the shadow came from?" The children shook their heads in disbelief, so they designed the shadow activity.
moving target
1. Through activities such as finding shadows, hiding shadows, and playing hand shadow games, let children know how shadows are formed and become interested in the natural phenomena around them.
2. Let the children describe the observed phenomenon in complete sentences.
Teaching emphases and difficulties
Understand how shadows are formed and be interested in the surrounding natural phenomena.
Activities to be prepared
Puppet, projector, movie, marker.
Activity process (it is not necessary to record all the conversations and activities between teachers and students in detail, but it is necessary to clearly reproduce the main links of the activity, that is, the beginning link, the basic link, the end link and the extension link. Note: Emphasis is placed on the basic links)
First, find a shadow
1, Puppet Shadow Show
The teacher manipulated the puppet monkey on the projector to make the monkey's shadow make various actions.
Q: What do you see? What is the monkey's shadow doing?
2. Children look for shadows.
Look, children, there is a little monkey's shadow on the wall. Come out and find your own shadow. The teacher closes the curtains, turns on the lights, and then plays music. The children look for shadows. )
Tell me where your shadow is. Let your shadow perform various actions and see which shadow has the most beautiful action. (Children perform various actions)
What was your shadow doing just now? How can shadows jump and walk?
Summary: shadows are really fun. If I move it, it will also move. If I do something, it will do something.
(turns off the light) Hey, where's the shadow? Why is it missing? (turns on the light) Why is the shadow coming out again? (Turn the light on and off again)
Summary: Shadow has something to do with light. When there is light, the shadow comes out; When there is no light, the shadow is gone.
Second, hide the shadows.
Let's play the game of hiding shadows. Let the children use their heads and hide the shadows. The teacher will come to them. Think about how to hide so that the teacher can't find your shadow. The child hides the shadow, the teacher looks for the shadow, and the child who finds the shadow stands aside.
(Ask the children who didn't find your shadow) Why didn't I find your shadow? Why are you hiding here?
Summary: Where there is no light, there is no shadow, so the teacher can't find it.
Play the game twice.
Third, play hand shadow games.
Today, the teacher prefers a performer who can play all kinds of hand shadow games. (Teacher performs hand shadow game)
What is the teacher performing? Which child can perform? (Children perform with puppets or hand shadows)
Tell me what you performed.
Summary: In the bright light, you can play various shadow play games.
Third, the extension of activities.
Find out where there are shadows in daily life. Find a good partner and play an interesting shadow game.
Teaching reflection
1. The content of this activity comes from children's spontaneous game activities, which are close to their lives and deeply loved by children.
2. In this activity, the goal is set properly, and children's original knowledge and experience are respected, so that children can achieve new cognitive goals by jumping.
3. The process of this activity is orderly, and the transition link is natural, which eliminates the time for children to wait passively.
4. Find the shadow of children among teachers and children, and find the shadow of children among other children, so that teachers and children, children and children can fully interact and enliven the classroom atmosphere.
5. Find the shadow link, let children actively explore ways to solve problems and give full play to their subjective initiative.
2. How did the shadow of the excellent teaching plan of kindergarten science activities come from?
Design intention: Shadow has always been a topic of interest to children, and integrating science education into children's lives is the embodiment of new ideas. The purpose of this activity is to let children discover the secret of shadow through experiments, let them know the close relationship between shadow and light, stimulate their curiosity and interest in shadow, learn scientific methods, develop a good scientific attitude, improve their ability to observe and find problems, and thus enrich their further understanding of shadow.
Activity goal: 1. Guide children to explore the secrets of shadows actively and interestingly.
2. Guide children through a series of observation and experimental activities to find that "light is blocked by objects and shadows will appear".
3. Through the communication between partners, let children have a further understanding and promotion of the formation of shadows.
Activity preparation: The room is arranged in dark light, with flashlights or lights, some animal toys, plastic toys, transparent and opaque paintings and color pictures. The rectangular carton has an opening on one side and rectangular openings on the top, left and right sides.
Activity flow: First, start: finger game (five monkeys on the swing)
Teacher: Look, children, who else is playing games besides our fingers? Guide children to tell the shadow of their fingers. Has the child seen the shadow of anything else? What do you see? Children are free to talk about the shadows they see.
Teacher: Children have seen so many shadows. Who knows how the shadows come from?
Discussion: communicate the shadows you have seen in groups, mobilize each child's existing experience, and tell the shadows you have observed on weekdays.
(Comments: Starting from children's cognition, exchange existing life experiences, let them speak freely, develop their language and thinking, and stimulate their interest in shadows, from which they can communicate and discuss constantly).
Children are free to tell how the shadows come from.
Teacher: Just now, I told so many secrets about shadows. Do the children want to discover the secret of the shadow for themselves?
Second, the basic process: hands-on operation, perception of shadows
1. Observation: Children take out flashlights and toys, and do shadow experiments in groups to see what they find. (Teacher participation)
The teacher asked the children to choose various animal toys to demonstrate in front of the lights and found the relationship between light and shadow.
2. Guide children to shine a flashlight on toys and hands, and discover the relationship between shadows and objects and light through their own experiments.
Teachers can guide children: turn on the flashlight and let the light shine on the wall-when there is no shadow, put your hand in front of the flashlight-the shadow of your hand will appear on the wall, turn off the flashlight and there will be no shadow of your hand on the wall, and guide children to describe the secret of the shadow they found in words. Teacher's summary: Only when there is an object blocking the light will there be a shadow, and the shadow will change with the change of the light position.
(Comment: True knowledge comes from practice, so that children can explore, discover and cultivate the ability of independent cooperation and inquiry, and understand the mystery of shadow through active discussion and careful observation)
3. Guide children to understand that there is a shadow when there is light: there is a shadow when there is light, and there is a light barrier, which are two indispensable conditions for generating shadows. Inspire children to think differently: What kind of "light" can reflect shadows, such as sunlight, moonlight, lights, candlelight and so on.
Step 4 add shadows
Teacher: The kitten can't find its own shadow. Where is its shadow? The teacher crayoned the kitten's shadow. Light from three different directions shines on the kitten, and its shadow position is different.
Children add shadows to objects (draw toys or objects on paper, draw sunlight), and teachers and children check whether there are any mistakes in adding pictures through experimental operations.
5. Play a video about shadow knowledge: the formation of shadow, understand that the shape and length of shadow change with the change of light direction, and the shadow is closely related to the illumination of light-the position of light changes, so does the shadow;
3. Knowledge about shadows
1. What is a shadow? Light travels in a straight line, and the object in front of the light source blocks the light, and a dark area called a shadow is formed where the light cannot shine.
The reason why we see this area is dark is because the light can't reach the back of the blocked object and can't be reflected into our eyes. An object can cast shadows of different shapes.
When the object is close to the light source, the shadow is larger because the object blocks a lot of light. As the object moves away from the light source, the shadow becomes smaller because the light blocked by the object decreases.
If you rotate an object, you will get different shapes of shadows. The edge of the shadow may be clear or blurred.
When an object is close to a place where a shadow is cast, such as a wall, the edge is clearly visible. When the object is far away from the place where the shadow is cast, the edge will become blurred.
Sometimes the middle part of the shadow is darker than the edge, the middle part is called umbra, and the brighter area is called penumbra. This shadow will appear when the light source is large.
In order to make all parts of the shadow equally dark, the light source must be small. The shadow outside depends on the weather.
In sunny, cloudless and sunny weather in Wan Li, the shadows are clear and dark. When the weather is cloudy and gloomy, it is difficult to see the shadow, because the sunlight is scattered by the tiny particles in the cloud and emitted in many directions, which means that the shadow is brighter than usual, so it is not easy to see.
2. The application of shadows by human beings has been very useful to human beings since ancient times. The movement of shadow has its fixed pattern, so we can predict the size and position of shadow.
When the earth rotates around its axis, everything on the earth's surface is illuminated by the sun. Mountains, trees and buildings all have shadows, but the position of shadows changes constantly throughout the day.
As the position of the sun changes, the shadow moves from one side of the object to the other. In the early morning and evening, the sun in the sky is very low, and the shadows are very long at these times.
At noon, the sun is high in the sky and the shadow is very short. The ancients found that the passage of time could be marked with a note, so they invented a sundial to let people know the local time.
3. The color of the shadow The color of the shadow depends on the light reflected by the shadow projection, and then the light blocked by the object is deducted. For example, a white wall reflects white light (in fact, white light contains various colors), so it looks white. When a part of the white light is blocked by an object, the light projected by the object on the wall becomes less, so the shadow part looks darker than the original wall.
If the object selectively blocks the light, the shadow will show different color changes instead of simple brightness changes. There are two possibilities as to how to selectively block the light. First of all, the object itself is selectively transparent (such as colored glass), so it will change the color of the shadow.
Secondly, there are more than one light source and different colors. The object only covers part of the light source. For example, if two light sources, red light and green light, are installed in different positions in the environment, the same object will cast shadows of two different colors, red and green, because it is illuminated by both red light and green light, it will appear yellow.
4. How to get on the fifth grade science shadow?
Jiangsu Education Publishing House, the first volume of "The Sun and Shadow" teaching plan (with supporting courseware) Author: Unknown Source: Yangzhong Foreign Language Primary School, I want to comment (0) Font: 377 clicks: Sun and Shadow Teaching goal: 1, I realize that the direction and length of the shadow change with time, and I know that this change is caused by the movement (vision) of the sun.
2. You can understand the relationship between objects and shadows by knowing shadows, and you can feel the relationship between sunlight and shadows by playing shadow games. 3. Experience the laws of science in the changes of ordinary things and consciously pay attention to the science around you.
Emphasis and Difficulties in Teaching Through a series of activities, I learned the regularity of shadow changes. Class time: the first week of teaching process: first introduce 1. The teacher said the riddle: Everyone has a good friend, with black body and black head, who walks with you in the sun and breaks up when it gets dark. (Answer: Shadow) 2. Students guess riddles.
3. Discussion: How do you know the answer is shadow? What else do you know about shadows? 4. Students exchange their understanding of shadows. Guess is a way that students like to see and hear.
Students have a process of thinking transformation from one class to another, and riddles can make students concentrate their thinking quickly and enter the classroom role quickly. At the same time, this riddle also implies a lot of scientific knowledge, such as what color the shadow is and how it is formed (the shadow needs light and so on). )] 2. Draw a shadow (1) Draw your own shadow.
Dialogue: Have you ever drawn a shadow? Has anyone ever painted their own shadow? Discussion: How are you going to draw your own shadow? What will your shadow look like? Take students to the playground to draw their own shadows. It is unprecedented that so many students come to the playground to draw shadows together.
The students are already looking forward to drawing their own shadows in the discussion. Although shadows are common, they just don't pay much attention to these common shadows, let alone their own.
In this activity, students will find many things in the process of drawing shadows: 1. The shadow and the sun are on both sides of people (things) respectively. 2. The bottom of the shadow is connected with people (things).
3. The shadow is gray-black (even in colorful clothes). 4. shadows are longer than people (note: 9 am). While obtaining these findings, they learned to cooperate and understand that sometimes it is difficult for a person to complete the task. Only by cooperating with each other can we draw our own shadow.
Process: ① Before departure, tell the students what they want to do. Give each student a piece of chalk and draw a shadow on the playground with the students.
(3) Draw footprints while drawing shadows, and write names in the shadows. (4) Remember your standing posture.
⑤ Let the students observe which side the sun is at this time, the shadow and the direction of the sun. On-the-spot observation is more convincing and lays the foundation for the following discussion.
6. After painting, get a new task. What can attract children more than drawing your own shadow?
Drawing shadows is not an end, but a means. The purpose is to let students leave traces of shadows, pave the way for observing shadows again and facilitate comparison. Students have feelings in the process of painting, experienced an interesting hands-on activity and found something.
Note: This is his own discovery. Draw shadows of other objects at this time, the students are still immersed in the fun of drawing shadows. Let the students draw the shadows of other objects. Let them find out which objects have shadows on the playground and draw their shadows.
If it is difficult to draw, draw a part, even the outermost line of the shadow. When students draw shadows of other objects, they will: 1. Search: Which objects have shadows? Realize that there is no shadow of an object, and there is no shadow of an object where there is no light or in the shadow of other objects.
2. Observation: What are these shadows like? Is there any connection with the shape of the object itself? 3. Contrast: Which of these shadows is bigger and which is smaller.
Which is brighter? (or which parts are brighter) which ones are darker? (or which parts are darker) 4. Communication: What shadow are you drawing? What did you find? Which ones are more interesting or special? (3) Make a simple heliograph and draw shadows. The teacher told the demonstration method: draw a mark in the middle of the cardboard, knead the plasticine into a chassis and put it in the center, insert a plastic stick on the plasticine, and mark the four directions of "southeast and northwest" on the cardboard. The teacher demonstrated the method of drawing shadow: put the sun shadow instrument flat in the southeast and northwest direction, measure the accurate direction with a compass, mark the end point of shadow, and record the time of measuring shadow.
Process: 1. Distribute student materials. 2. Students make simple solar shadow instruments.
3. Operate the recording rod shadow. [In this process, we must explain the operation method in detail, because it is a scientific learning method to teach students. When placing the heliograph, be sure to measure the orientation with a compass to ensure scientific nature.
Third, guess the change of the shadow. Organize the students to sit in a circle, with the teacher participating. Guess: Will the shadow be the same after a while? The first thing that students think of is that shadows will move.
However, this is not enough. Then, the teacher should let the students guess how the shadow will move. In which direction? Why did you go in that direction? Besides the change of direction, what other changes have taken place? Let the students fully express their opinions and ask them to explain why they made such a guess-in order to infiltrate the students: the guess should also be well-founded. In order to cultivate students' ability to make more accurate predictions about future things based on existing experience.
Guess is a very important link from problem to practice. This kind of speculation is often very effective for scientific discovery and scientific generalization. It is the first step on the road of "engaging in science", which often points out the direction for scientific inquiry, collects facts, analyzes and sorts them out, verifies them and corrects this direction.
After the students make a guess, they don't need the teacher to assign tasks. I'm sure they will observe the shadows on the ground again. [4] Students observe the shadow again and discuss it. 1. The teacher asked: Will the shadow really change as you said? 2. Students observe the shadow again.
They will be surprised to find that standing on their footprints, the shadows are different from the original ones, especially the shadows of fixed objects, and the changes are obvious. 3. Exchange discussion: (1) What did you find? Explain what?
5. Little scientific knowledge
Benjamin Franklin accidentally thought of inventing the lightning rod: Franklin's most famous discovery was the unification of heaven and earth electricity, which broke people's superstition about lightning.
In the process of discharge experiment with Leiden bottle, Franklin could not help but think of lightning in the sky in the face of the flash and crack of electric spark. He realized that the spark in the Leiden bottle might be a small lightning. In order to test this idea, lightning in the sky must be brought to the ground.
1752 On a thunderstorm day in July, Franklin made a big kite with silk, put a tapering iron wire on the top of the kite, and connected the iron wire with the ground with silk thread. At the end of the silk thread is tied a copper key, which is in a Leyden bottle. Franklin put the kite in the sky, and a flash of lightning struck, only to see the hairs on the silk thread stand up and put his hand close to the copper key, which is an electric spark.
The Temple of Heaven was finally caught. Franklin discovered all the phenomena that the Leiden bottle that stored the sky electricity could produce the earth electricity, which proved that the sky electricity and the earth electricity were the same.
1747, Franklin discovered the phenomenon that the tip is easier to discharge from the Leyden bottle experiment. After he discovered the unification of sky electricity and ground electricity, he immediately thought of using the principle of tip discharge to introduce powerful lightning in the sky into the ground to avoid buildings being struck by lightning. 1760, Franklin erected a lightning rod on a building in Philadelphia, and the effect was very remarkable.
Newton was killed by an apple and discovered the law of gravity. Russian chemist Mendeleev (1834~ 1907) was born in Siberia.
He loved labor, nature and hard work since he was a child. 1860, Mendeleev was deeply troubled by the lack of systematicness in inorganic chemistry when considering the writing plan of the book Principles of Chemistry.
Therefore, he began to collect information about the nature of various known elements and related data, and collected all the achievements made by predecessors in practice. The long-term practice and cognitive activities of human beings on the issue of elements have provided him with rich materials.
On the basis of studying predecessors' achievements, he found that some elements have similarities besides characteristics. For example, fluorine, chlorine, bromine and iodine of halogen elements are known to have similar properties; Alkali metal elements such as lithium, sodium and potassium are oxidized quickly in the air, so they can only exist in the form of compounds in nature. Some metals, such as copper, silver and gold, can be kept in the air for a long time without corrosion, which is why they are called precious metals.
So Mendeleev began to try to arrange these elements. He made a rectangular cardboard for each element.
Element symbols, atomic weights, element properties and their compounds are written on each rectangular cardboard. Then nail them to the wall of the laboratory and arrange them repeatedly.
After a series of queues, he discovered the regularity of chemical properties of elements. Therefore, when someone regarded Mendeleev's discovery of the periodic law of elements as simple and easily said that he got this great discovery by playing poker, Mendeleev seriously replied that it took him about 20 years to publish the periodic law of elements in 1869.
He picked out the chemical elements from the chaotic maze. In addition, because of his great courage and confidence, he was not afraid of famous critics, laughed at, practiced and publicized his own views, and finally he was widely recognized.
The periodic law of elements reveals a very important and interesting law: the properties of elements change periodically with the increase of atomic weight, but they are not simply repeated. According to this truth, Mendeleev not only corrected some wrong atomic weights, but also predicted the existence of more than 15 unknown elements.
As a result, Mendeleev discovered three elements when he was still alive. 1875, French chemist Bois Baudrin discovered the first filled element, named gallium.
All the properties of this element are the same as Mendeleev predicted, but the proportion is inconsistent. Mendeleev wrote a letter to the Paris Academy of Sciences, pointing out that the proportion of gallium should be around 5.9, not 4.7.
At that time, the gallium was still in the hands of Boyce Baldwin, and Mendeleev had never seen it. This incident surprised Boise Baudrin, so he tried to purify and re-measure the proportion of gallium, and the result confirmed Mendeleev's prediction that the proportion was indeed 5.94.
This result greatly improves people's understanding of the periodic law of elements, and also shows that many scientific theories are called truth, not when scientists create these theories, but when they are constantly confirmed by practice. When Mendeleev predicted new elements through the periodic table, some scientists said that he arrogantly invented some nonexistent elements.
Through practice, Mendeleev's theory has been paid more and more attention. Later, according to the theory of periodic law, people sorted out and classified more than 100 elements that had been discovered, and listed today's periodic table of chemical elements, which was posted on the laboratory wall and arranged at the back of the dictionary.
It is a lesson that every student must learn and master when studying chemistry. Now we know that in the vast universe of human life, all substances are composed of this 100 element, including ourselves.
However, what are chemical elements? Chemical elements are the general name of the same kind of atoms. So people often say that atoms are the "basic bricks" that make up the material world, which is still possible in a certain sense.
But the periodic law of chemical elements shows that chemical elements do not exist in isolation and are not related to each other. These facts mean that elements and atoms must have their own internal laws.
There has been a revolution in the theory of material structure. At last, at the end of 19, there was a new development in practice and radioactive elements and electrons were discovered, which was originally an excellent opportunity to uncover the inside story of atoms.
However, Mendeleev was puzzled in practice. On the one hand, he is afraid that these findings "will complicate things" and shake "the foundation of the whole world outlook"; On the other hand, I think this "will be a very interesting thing ... the reason for the periodic law may be revealed".
But Mendeleev himself died in 1907 with this contradictory thought on the eve of uncovering the essence of periodic law. Mendelia
6. How to get on the fifth grade science shadow?
Jiangsu Education Publishing House, the first volume of "The Sun and Shadow" teaching plan (with supporting courseware) Author: Unknown Source: Yangzhong Foreign Language Primary School, I want to comment (0) Font: 377 clicks: Sun and Shadow Teaching goal: 1, I realize that the direction and length of the shadow change with time, and I know that this change is caused by the movement (vision) of the sun.
2. You can understand the relationship between objects and shadows by knowing shadows, and you can feel the relationship between sunlight and shadows by playing shadow games. 3. Experience the laws of science in the changes of ordinary things and consciously pay attention to the science around you.
Emphasis and Difficulties in Teaching Through a series of activities, I learned the regularity of shadow changes. Class time: the first week of teaching process: first introduce 1. The teacher said the riddle: Everyone has a good friend, with black body and black head, who walks with you in the sun and breaks up when it gets dark. (Answer: Shadow) 2. Students guess riddles.
3. Discussion: How do you know the answer is shadow? What else do you know about shadows? 4. Students exchange their understanding of shadows. Guess is a way that students like to see and hear.
Students have a process of thinking transformation from one class to another, and riddles can make students concentrate their thinking quickly and enter the classroom role quickly. At the same time, this riddle also implies a lot of scientific knowledge, such as what color the shadow is and how it is formed (the shadow needs light and so on). )] 2. Draw a shadow (1) Draw your own shadow.
Dialogue: Have you ever drawn a shadow? Has anyone ever painted their own shadow? Discussion: How are you going to draw your own shadow? What will your shadow look like? Take students to the playground to draw their own shadows. It is unprecedented that so many students come to the playground to draw shadows together.
The students are already looking forward to drawing their own shadows in the discussion. Although shadows are common, they just don't pay much attention to these common shadows, let alone their own.
In this activity, students will find many things in the process of drawing shadows: 1. The shadow and the sun are on both sides of people (things) respectively. 2. The bottom of the shadow is connected with people (things).
3. The shadow is gray-black (even in colorful clothes). 4. shadows are longer than people (note: 9 am). While obtaining these findings, they learned to cooperate and understand that sometimes it is difficult for a person to complete the task. Only by cooperating with each other can we draw our own shadow.
Process: ① Before departure, tell the students what they want to do. Give each student a piece of chalk and draw a shadow on the playground with the students.
(3) Draw footprints while drawing shadows, and write names in the shadows. (4) Remember your standing posture.
⑤ Let the students observe which side the sun is at this time, the shadow and the direction of the sun. On-the-spot observation is more convincing and lays the foundation for the following discussion.
6. After painting, get a new task. What can attract children more than drawing your own shadow?
Drawing shadows is not an end, but a means. The purpose is to let students leave traces of shadows, pave the way for observing shadows again and facilitate comparison. Students have feelings in the process of painting, experienced an interesting hands-on activity and found something.
Note: This is his own discovery. Draw shadows of other objects at this time, the students are still immersed in the fun of drawing shadows. Let the students draw the shadows of other objects. Let them find out which objects have shadows on the playground and draw their shadows.
If it is difficult to draw, draw a part, even the outermost line of the shadow. When students draw shadows of other objects, they will: 1. Search: Which objects have shadows? Realize that there is no shadow of an object, and there is no shadow of an object where there is no light or in the shadow of other objects.
2. Observation: What are these shadows like? Is there any connection with the shape of the object itself? 3. Contrast: Which of these shadows is bigger and which is smaller.
Which is brighter? (or which parts are brighter) which ones are darker? (or which parts are darker) 4. Communication: What shadow are you drawing? What did you find? Which ones are more interesting or special? (3) Make a simple heliograph and draw shadows. The teacher told the demonstration method: draw a mark in the middle of the cardboard, knead the plasticine into a chassis and put it in the center, insert a plastic stick on the plasticine, and mark the four directions of "southeast and northwest" on the cardboard. The teacher demonstrated the method of drawing shadows: lay the sun shadow instrument horizontally in the southeast and northwest direction, measure the accurate direction with a compass, mark the end point of shadows, and record the time of measuring shadows.
Process: 1. Distribute student materials. 2. Students make simple solar shadow instruments.
3. Operate the recording rod shadow. [In this process, we must explain the operation method in detail, because it is a scientific learning method to teach students. When placing the heliograph, be sure to measure the orientation with a compass to ensure scientificity.
Third, guess the change of the shadow. Organize the students to sit in a circle, with the teacher participating. Guess: Will the shadow be the same after a while? The first thing that students think of is that shadows will move.
However, this is not enough. Then, the teacher should let the students guess how the shadow will move. In which direction? Why did you go in that direction? Besides the change of direction, what other changes have taken place? Let the students fully express their opinions and ask them to explain why they made such a guess-in order to infiltrate the students: the guess should also be well-founded. In order to cultivate students' ability to make more accurate predictions about future things based on existing experience.
Guess is a very important link from problem to practice. This kind of speculation is often very effective for scientific discovery and scientific generalization. It is the first step on the road of "engaging in science", which often points out the direction for scientific inquiry, collects facts, analyzes and sorts them out, verifies them and corrects this direction.
After the students make a guess, they don't need the teacher to assign tasks. I'm sure they will observe the shadows on the ground again. [4] Students observe the shadow again and discuss it. 1. The teacher asked: Will the shadow really change as you said? 2. Students observe the shadow again.
They will be surprised to find that standing on their footprints, the shadows are different from the original ones, especially the shadows of fixed objects, and the changes are obvious. 3. Exchange discussion: (1) What did you find? Explain what?