A preliminary understanding of the angle teaching plan 1 1. Review objectives
1, know the length units of meters and centimeters, initially establish the length concepts of 1 meter and 1 centimeter, and know the teaching plans of 1 meter = 100 cm and 10 public classes.
2, will use a ruler to measure the length of the object and draw the length of the line segment.
3, will measure the length of the object.
4. Know the angle and right angle, and know the names of all parts of the angle.
5. Triangle will be used to judge whether an angle is a right angle; Can draw angles and right angles.
Second, review the important and difficult points
1, measure the length of the object correctly with a scale.
2. Conversion between meters and centimeters.
3. Draw the length of the specified line segment.
4. Know right angles and draw right angles.
5. Symbols of angles and right angles are commonly used.
Third, teaching preparation teaching courseware
A few exercises
Fourth, the teaching process design
1, set doubts to stimulate interest
Teacher: I saw a composition written by a third-grade child yesterday and thought it was very funny. Today, I want to bring it to you. do you want to hear it ?
(Student: Thinking)
On Saturday morning, my mother and I went to Xinhua Bookstore by bus. The car traveled six centimeters and stopped at a crossroads. After getting off the bus, my mother and I walked about 10 cm and finally arrived at Xinhua Bookstore. There are so many books in Xinhua Bookstore! Bookstores are surrounded by bookshelves 2 cm high. I stood on tiptoe and compared it. The bookshelf is much taller than me! I chose an excellent composition on the bookshelf, which is 2m long, 14cm wide and 2m thick. I like this book very much, it is a good helper for my study!
Teacher: After listening to this child's composition, I found many people laughing! Tell me why you are laughing.
Student: The length unit in the composition is wrong.
Teacher: Can you point out what's wrong?
Health: ......
Teacher: How are you going to help the child revise his composition?
Health: ......
2. Review the main points
Teacher: It seems that the child must have failed to learn the unit knowledge of length units in the second grade, so he made so many jokes.
Teacher: If he wants you to help him make up lessons, what length do you want to tell him?
① What are the length units?
What's the relationship between meters and centimeters?
③ How to measure the length of an object with a ruler?
Which part of your body is about 1 meter long? Which part is about 1 cm in length?
⑤ Who can measure the length?
3. Consolidate exercises (reward five-pointed stars)
(1) Measure the length of an object whose starting point is not zero scale.
(2) Fill in the appropriate units.
⑶ Determine which segments are and measure the length of the segments.
(4) Estimated length (a reference, teaching plan "10 open class teaching plan". Estimate others)
4. Preliminary understanding of angle (introduction)
Teacher: Seeing the five-pointed star in their hands, do you remember another knowledge we learned not long ago?
Health: Horn
Teacher: You mean, this is a horn? Or is there a horn in it?
Health: It's a picture with corners in it.
Teacher: Then what is a horn? What are the characteristics of horns? )
Health: 1 vertex and 2 edges (2 edges cannot be bent)
Classification: (Courseware)
Teacher: Look carefully. Can you classify them? And explain why.
(Group communication)
(Designated report)
It is divided into two types: angle and non-angle (reason: angle is composed of 1 vertices and two sides) (non-angle is hidden), and the angles are arranged in a row from large to small.
Health: ③ ① ⑤
Teacher: How do you compare?
Health: you can compare them at right angles first, and then arrange them (you can arrange them directly according to the size of both sides)
Teacher: Figure ③ is so small, why is it the largest?
Health: both sides are big; It is related to the size of both sides.
The teacher shows the change diagram of 1 diagram.
Teacher: Which of these two angles is bigger? (Summary: The angle has nothing to do with the length of the sides, but only with the divergence of the two sides)
Teacher: Next, let's draw a corner. Draw a right angle first, then draw an angle larger than the right angle, and finally draw an angle smaller than the right angle. (Comment on the symbols drawn by students) Special emphasis is placed on right-angle symbols and general corners.
Teacher: What should I do if I want to know if it is a right angle?
Health: Compare right angles on triangles.
Teacher: Who can help me verify the 50 cents just now?
(name and posture)
Teacher: How did you set it up?
Health: the vertices are aligned, one side is aligned, and then the other side is aligned.
Teacher: Check the right angle you draw in the same way and correct the mistakes.
Teacher: We have known angles before, and we also know how to draw them. Is there anything else we haven't discussed about the angle?
Health: Count the horns.
Teacher: What is the most reliable way to count angles?
Student: Count with a pencil.
Get to know the lesson plan in the corner II. Teaching content: Mathematics, the standard experimental textbook of compulsory education curriculum (the first volume of the second grade), pages 38-39, a preliminary understanding of the example 1, example 2, a corner of the third volume.
Default target:
1. Make students experience the process of finding and understanding angles from objects, initially establish the concept of angles, and know the names of various parts of angles.
2. Learn to draw angles with a ruler at first.
3. Cultivate students' observation ability, practical operation ability and spatial concept, realize the ubiquitous mathematics around them, and stimulate students' interest in learning mathematics.
Teaching emphasis: help students form the correct representation of the angle and know the names of each part of the angle.
Teaching difficulty: I can draw angles with a ruler.
Teaching process:
Talk before class: children, we met for the second time today. Are we old friends? Do you know what kind of students my old friend likes? I prefer children who ask questions. What do you want to ask me?
First, stimulate interest and introduce new courses.
Little friend, did you bring this math friend? (Triangle) How to greet this good friend? How do you feel when you shake hands? (sharp, a little painful ...) Let me try, really, how can it bite? (Angle) So it is. (blackboard writing: corner)
Second, cooperate and exchange, and explore new knowledge.
1. Around us, many objects have horns. Can you find them? Let's talk about the corners you see in the group first and see which group finds the most corners. (Find the corner in group activities) Which group of students want to show you the corner found by your group first? The children are great. They found so many horns.
2. The teacher understood that the angle pointed by the child turned out to be such a figure, and the primary school mathematics teaching plan "The Preliminary Understanding of the Angle in Book 3". (Multimedia Demo) Are they corners?
3. What is the angle in your mind? (Talking to each other in the group) Will you send a representative from each group to draw an imaginary corner of your group? What do you want to say about the corners drawn on the blackboard? Are all the corners drawn by the children correct? We'll see later. )
But the teacher understands a little. It seems that a corner is more than just a point. (Multimedia Demo) This point is just the vertex of the corner. What else is there? There are also two straight lines. These two straight lines are the sides of the angle, and this figure is the angle. Children, order together. (Then demonstrate the vertices and edges of two corners with multimedia. Students imitate their fingers. )
5. Show the corners around you to your classmates in this way. What do these corners have in common? (blackboard writing: a corner has a vertex and two sides)
6. The child closes his eyes, leaves the horn in his head and asks: Is there a horn in his head? What is it like?
7. Draw a corner: We know this corner just now, and we have this corner in our mind. Can you draw this corner on the paper?
(1) How are you going to draw it?
(2) How does the computer teacher draw corners? Let's take another look. Yes, draw a vertex first, and then draw two lines in different directions from one point with a ruler to draw an angle. Children also draw two corners in different directions in the right way. After drawing, talk about the names of each part of the angle in the group. Teacher: Look at the corners painted by your group. What do you want to say to them? You really appreciate people.
8. Summary: What new knowledge do you have about diagonals after studying here?
Third, consolidate and expand and improve the debate.
1. Grandpa Jiao's birthday is coming, and many members of Jiao's family are sent by small animals. Come and see, children. What do you want to say to the little animals?
2. After learning this, what do you want to say to these corners on the blackboard?
3. Make a corner: Take out the wool, stick, paper and straw and ask: Is there a corner in it? Please be a magician once, and make a corner for Grandpa Jiao. Who will introduce you? How did you do that? Why is it also a horn? Children are really smart. They make different speakers with different materials, but what do they have in common?
4. The little monkey came in a hurry and said, Look, look, I just have more horns. Did you get a look at him? Anyone can send as many horns to Grandpa Jiao as a little monkey. What graphics do you want to send?
5. Now the pig understands. He not only straightened this side into an angle, but also added a line. Guess how many corners the pig served?
6. You all sent so many horns to Grandpa Jiao, and the little monkey was anxious. Mother monkey said, "Don't worry, don't worry, as long as you are on this triangle … it will grow more horns." Do you have any ideas? Then let's try it. Children can also go to other groups to see which group draws the most beautiful and has the most angles. )
A preliminary understanding of lesson plan 3 from the perspective of teaching material analysis
The content of "Preliminary Understanding of Corner" is the beginning of the third volume "Corner and Right Angle", which is based on students' preliminary understanding of rectangle, square and triangle. As an important part of geometric shape, the characteristics of angle, the names of each part and the drawing method are the focus of learning. It is difficult to compare the sizes of angles by abstracting the graphs of angles intuitively. In addition, learning this part of knowledge also lays the foundation for the classification of learning angles of senior students in the future. Therefore, in the initial class of angle understanding, students should be fully helped to establish the appearance of angle, at the same time, students' interest in learning collective knowledge should be stimulated in this process, and students' autonomous learning and cooperative learning should be cultivated.
Analysis of learning situation
"Children's intellectual activities are closely related to their actions on the surrounding objects, that is, children's understanding comes from their actions and the activities of objects." Trumpets are everywhere in students' lives. In teaching, teachers should make full use of this factor to guide students to understand the angle.
Teaching objectives
1, knowledge and skills: enable students to get to know the angle, know the names of each part of the angle, intuitively understand the size of the angle and draw the angle.
2. Process and method: To cultivate students' preliminary observation and operation ability through the practical activities of angle folding and angle making.
3. Emotion and attitude: Through students' corner finding and courseware demonstration, students can feel the close connection between mathematics and daily life and stimulate their interest in learning.
Teaching emphases and difficulties
1, get a preliminary understanding of the angle and know the names of each part of the angle.
2, can identify the angle.
3. Learn to draw corners with a ruler.