Speech on "Preliminary Understanding of Horn"

In the actual teaching activities of teachers, it is necessary to design a lecture carefully, which will help students understand and master systematic knowledge. How to write the speech? The following is a sample essay of the lecture on "Preliminary Understanding of the Corner" compiled by me. Welcome to share.

The draft of "Preliminary Understanding of Horn" is 1. First, teaching materials.

Teaching materials:

A preliminary understanding of the first class hour in the corner of the third unit of the second grade of the compulsory education curriculum standard experimental textbook "Primary Mathematics"

(B) the status and role of teaching materials

The preliminary understanding of angle is an abstract graphic concept that students come into contact with on the basis of understanding some basic graphics such as rectangle, square and triangle. In the textbook, students are not required to master the definition of angle, but only to know the shape of angle, the names of various parts of angle and draw the angle with a ruler. Students understand the basic characteristics of corners through practical activities such as folding corners, drawing corners and making corners. If students master this part skillfully, it will lay a foundation for further study of geometry.

(3) Teaching objectives:

1, combined with life scenes, can correctly point out the angle of the object surface or plane figure and know the names of each part of the angle.

2. Learn to draw an angle with a ruler, make an angle with different materials and methods, and compare angles preliminarily, so as to develop students' spatial concept, imagination and operational ability.

(D) the focus and difficulty of teaching

Teaching emphasis: let students form the correct representation of angle, know the names of various parts of angle, and initially learn how to draw angle with a ruler.

Teaching difficulties: Let students understand through intuitive perception that the size of an angle has nothing to do with its side length, but is related to the size of its openings on both sides.

(5) Prepare teaching AIDS and learning tools.

Teaching AIDS: multimedia courseware, triangle, straw, several different sizes of corners, etc.

Learning tools: triangles, straws, several angles of different sizes, etc.

Second, oral teaching methods

According to the arrangement characteristics of teaching materials, in order to effectively highlight key points and break through difficulties, based on the development of students, I mainly adopt the following two methods:

1, situational teaching method. In teaching, I pay attention to creating life scenes that students are familiar with, and closely link the understanding of corners with life scenes, so that students can experience that mathematics is around us in the process of learning.

2. Guided inquiry method. The knowledge and thinking of junior students have certain limitations, and most students' operational ability, thinking ability and oral expression ability can not be well combined. In view of this situation, I organize students to carry out inquiry learning activities by guiding inquiry.

Third, theoretical study.

It is particularly important to pay attention to the guidance of students' learning methods in teaching. Observation and discovery, hands-on operation, independent inquiry and cooperative communication are the main learning styles of the students in this class. Let them perceive the basic characteristics of angle in a series of activities such as finding, folding, drawing, comparing and speaking.

Fourth, talk about the teaching process:

1) Create situations and introduce new lessons.

1, students, we are exposed to all kinds of graphics every day in our lives. (Show a triangle) Do you know why it is called "triangle"? Who wants to point up (most students refer to the corner)?

Teacher: It turns out that the angle in students' minds is like this. (Click on the blackboard) Is this the corner? It seems that there is still a lot of knowledge in pointing! Today, let's get to know the angle (blackboard title: a preliminary understanding of the angle)

Intention: According to the characteristics of senior two students, let them participate in learning with curiosity and interest from the beginning, starting with the graphics they know and the existing experience and knowledge. At the same time, create a relaxed, democratic and lively classroom atmosphere to make students feel happy and refreshed. This positive emotion can easily open the floodgates of thinking and sprout creativity.

2) Guide inquiry and learn new knowledge.

This link is the center of classroom teaching, and the curriculum standard points out that "students should pay attention to obtaining the intuitive experience of simple geometry and plane graphics in activities such as observation and operation." Therefore, the teaching of this link is divided into four activities to explore:

1, connecting with the actual angle-establishing the appearance of "angle"

(1) Take the corner on the cover of a textbook as an example and ask: How can I correctly point out the corner? Guide students to discuss and communicate. Let the students learn the correct pointing method, and point to each other at the same table.

By pointing to the angle, make clear the impression of the angle in students' minds.

(2) Observe the theme map of the textbook and show the corner you found to the students in the group. This exercise not only provides students with an opportunity to express themselves, but also makes them feel that the corner is around us.

2. Hands-on understanding of angles-exploring the same characteristics of angles.

This is the focus of teaching. Psychologists show that children's wisdom comes from their fingertips. Therefore, the design of my activity is based on students' hands-on operation, which is completed in four steps:

(1) Folding: Let the students first fold a favorite corner with an irregular piece of paper.

(2) Comparison: Guide students to observe and compare the folding angles. In the process of comparison, let students feel that the angles are big and small.

(3) Touch: Then let the students touch the corner they have folded, so that they can fully feel that the corner has a sharp corner and two straight sides through personal experience.

(4) Say: Then I organize students to exchange the feelings of touching the angle, and gradually abstract the geometric figure of the angle from the physical object. According to the student's report, I write on the blackboard, and then ask the students to look at the blackboard and name the parts in the corner.

In this way, through the close combination of operation, observation and language expression, students will have a clearer understanding of diagonal representation and basic characteristics, thus solving the key points of this lesson.

3, the actual operation Angle diagram

The Curriculum Standard points out that "students in this period should carry out simple measurement activities and establish a preliminary concept of space." According to this concept, I will draw the corner in three steps:

(1) Take a look: First, let students watch the process of drawing corners through courseware, so that students can have a preliminary understanding of the steps of drawing corners and cultivate their ability of independent learning.

(2) Drawing: Under the teacher's demonstration, teachers and students draw the same corner. Through the teacher's blackboard writing, it is helpful to standardize the students' methods of drawing corners. At the same time, students are encouraged to try boldly, draw different angles and cultivate their innovative consciousness.

(3) Say: Guide students to summarize the characteristics and drawing methods of angles.

4. Make an angle-understand what this angle is related to and has nothing to do with.

This is the difficulty of teaching. In teaching, I first use learning tools to establish an intuitive angle. Then feel the change of angle through game activities. Specifically divided into two steps:

(1) Game: Whose hand is clever?

Fold the straw into a movable angle, so that students can realize that the angle is related to the size of both sides.

This activity enables students to transition from a static perspective to a dynamic perspective. Let the students understand vividly the essential characteristics of "the size of a corner is related to the size of its openings on both sides" in the game.

(2) Game: Who has a good eye?

Show two prepared corners with the same size and different sides. Let the students guess who is older and who is younger. By comparison, the angle has nothing to do with the length of both sides.

In this way, the difficulties are dispersed into two games, so that they can vividly and profoundly understand that the size of the angle is related to the size of both sides, and has nothing to do with the length of both sides.

3) Set exercises skillfully to consolidate and improve.

Complete Exercise 8, Question 3 and Question 4 in the textbook.

4) Class summary.

Students, what have you gained from learning this lesson?

5) Design of blackboard writing

Writing on the blackboard is the soul of a class, so my writing on the blackboard reflects the knowledge and simplicity, so that students can see at a glance, better grasp the key points and break through the difficulties.

The angle of preliminary understanding, lecture notes 2, teaching materials

The teaching content of preliminary understanding of angle is based on students' preliminary understanding of rectangle, square and triangle. Students' mastery of this part also lays a foundation for further study and study of triangles, rectangles and squares, and plays a role in connecting the past with the future. From the beginning, the textbook starts with the familiar campus life scenes, guiding students to observe the angle in the real thing and let them initially perceive the angle. Through the example of 1, the angle is extracted from three kinds of objects. On this basis, the names of various parts of the angle are introduced, and the characteristics of the angle are explained. Then, through practical activities such as folding the angle with paper and moving the angle with hard paper strips, students can further perceive the angle. Finally, let the students draw the angle by hand. The arrangement of teaching materials is based on students' existing knowledge and life experience, and according to children's age characteristics, let them practice, explore independently and cooperate with each other, which is in line with the concept advocated by mathematics curriculum standards.

Second, talk about teaching objectives

According to the understanding of teaching materials and students' cognitive level, I set the following three teaching objectives:

1. Knowledge objective: Let students know the angle, the names of each part of the angle, the size of the angle, and learn to draw the angle with a ruler.

2. Ability goal: By allowing students to observe, operate, analyze and compare, cultivate students' observation ability, hands-on operation ability and abstract thinking ability.

3. Emotional goal: to cultivate students' team spirit of mutual assistance and cooperation; Let students know that there are corners in life and cultivate students' interest in learning mathematics.

Third, talk about the key points and difficulties in teaching.

Key points: establish the concept of horn and know the names of teaching parts.

Difficulties: Initially establish the concept of angle size and guide students to draw angles.

Fourth, talk about teaching strategies.

Corner is abstract for the second grade students in primary school. Therefore, in order to help students better understand the corner, observation, operation, demonstration, self-study discussion and other methods are organically run through all aspects of teaching, guiding students to abstract and summarize on the basis of perception. Let students know the cognitive law from perception to representation. Let students learn through observation and analysis, hands-on thinking, practice consolidation and cooperative learning.

Through practical activities such as "finding, recognizing, folding, doing and drawing", students are mobilized to realize the truth, thus establishing the appearance of the angle, enriching diagonal knowledge, developing students' concept of space, and embodying the idea of letting students experience the process of abstracting practical problems into mathematical models.

V. Presentation aids and learning tools

Teaching AIDS: multimedia courseware, triangle, preparation angle, magnet, round paper.

Learning tools: triangles, ready-made angles

Sixth, talk about the teaching process.

1, review and introduction

After showing the rectangles, squares and triangles, please tell the students what the following figures are. After that, the teacher will explain: Today, we will learn a new figure different from rectangle, square and triangle: it is a corner. This lesson is just a preliminary understanding (blackboard title: a preliminary understanding of the corner)

2. Create situations and reveal topics.

(1) Show a picture of a corner of the school, let the students observe and tell where there is a corner, and then the courseware marks the corner in obvious red on the campus map.

There are pictures of scissors, cans and taps in the courseware. Let the students observe and say where there are angles again, and please write down the angles on the surface of the object. Then ask the students to observe these three angles carefully and tell them what you find in common. Students discuss in groups based on independent thinking. Here, let students abstract from the perspective of observing physical objects, let students experience the process of abstracting mathematical knowledge, feel the authenticity of mathematical knowledge, learn to observe practical problems from the perspective of mathematics, and thus stimulate students' interest in exploring mathematics.

After group discussion, report and guide the students to conclude that they all have sharp parts and straight lines. At this time, the teacher takes a corner as an example in the courseware and tells the students that the sharp part is called the vertex of the corner and the straight line is called the edge of the corner. Perhaps at the beginning of class, students' perspective of knowing themselves is accumulated in daily life, which is vague and non-mathematical. However, at this time, students establish a correct representation of the angle through observation and comparison.

Next, ask two students to come up and point to the vertices and sides of the other two corners on the screen (the purpose of this session is to let the students deeply understand that a corner is composed of two sides of a vertex)

Summary: How many vertices does a corner have? How many sides? Write the answers on the blackboard.

(2) Judging "the first question in the exercise"

Look, which of the following figures is a corner and which is not? Let the students judge not the angle. Tell me why it's not an angle. The purpose of this link is also to let students feel further that a corner must be composed of a vertex and two sides. )

(3) Find the corner of life

Tell children that there are not only horns in these pictures, but also many horns around us. Teachers first demonstrate and point out the corners on the blackboard, and then ask students to find and talk with their deskmates in the classroom to see which objects have corners on their surfaces and point out the vertices and sides of the corners. After the group activities, please ask some students to report the corners they found to the class, and point out the vertices and two sides.

The teacher explained that there are so many corners in a classroom, so there are more corners in our daily life. You can look for them in after-school life.

This link allows students to consolidate the corners in mathematics, let them return to life, and use the mathematical knowledge they have learned to find corners more rationally. This design makes students feel the role of mathematics in life, cultivates children's consciousness and ability to observe the world around them with mathematical eyes, and also gives children a successful experience, which cultivates children's interest in learning mathematics and confidence in learning mathematics well.

3. Folding angle

After the students form a certain image in their minds, let them fold the corner and fold the prepared paper to their favorite corner under the guidance of the teacher. Then let the students touch the angle, and feel that the vertex of the angle is sharp and the two sides of the angle are straight. This process can make students feel the sense of touch from the vision and further deepen their understanding of the diagonal.

4. Angle of activity

How to change the movement angle of students' hands? Make it bigger. How come? Make it smaller. How come? Smaller. How come? If the edge of the finished corner is cut off a little, will the size of the corner change? If the side of the angle is lengthened a little, does the size of the angle change? Organize students to discuss: What does the angle have to do with it? Nothing to do with what? And write the conclusion on the blackboard. (This link enables students to have some intuitive understanding of the size of the diagonal, and initially perceive the method of comparing the size of the diagonal. Through practical operation, experience, thinking, communication and other activities, let students realize that the size of the angle is related to the size of the two sides. )

5. Draw corners by hand

The teacher explained: As long as you know the corner, you can bend it. Do you want to draw a beautiful corner yourself? Then the teacher first demonstrated drawing a corner, emphasizing drawing with a ruler, and then asked the students to try to draw a corner. Teachers patrol to help students with difficulties. After the students have finished drawing, please ask several students to put the drawn works under the slides for the whole class to see, and other students will evaluate their works.

6. Summary

(1) Children, this lesson is over. What did you get from this lesson?

(2) Through this lesson, the children have a preliminary understanding of the corner. In fact, there are still many secrets in the corner world that we haven't discovered. We will continue to explore its secrets in the next lesson.

7, homework arrangement

A preliminary understanding of the angle, lecture 3 I. Speaking of teaching materials:

1, teaching material analysis:

The initial understanding of angle is a general graphic concept that students come into contact with on the basis of understanding some basic graphics such as rectangle, square and triangle. For junior students who have just entered the second grade, such general graphics will make them find it difficult to understand. Therefore, it is necessary to lay a good foundation for students in teaching, and provide the necessary conditions for further study of the meaning of angle and systematic study of right-angle knowledge in the future.

2. Teaching objectives:

Knowledge goal: know the angle, know the names of each part of the angle, and learn to draw the angle with a ruler.

Ability goal: through teaching, cultivate students' preliminary observation ability, hands-on operation ability and language expression ability, and distinguish angles from physical objects and plane graphics.

Moral education goal: let students know that many objects around them have horns, understand the close relationship between mathematics and daily life, develop good study habits from an early age, and cultivate their innovative spirit and bold attempts.

3, teaching focus:

Diagonal understanding.

4, teaching difficulties:

The size of the angle is related to the size of both sides, but not to the length of both sides.

5, teaching material arrangement characteristics:

Starting with the real thing, let the students point, touch and feel the shape of the angle, and then use the folded angle to find the characteristics of the angle. The third layer, using the change of the activity angle, extracts the relationship between the angle and what, and finally draws the angle. Generally speaking, the arrangement of teaching materials in small steps, from intuitive image to general use, conforms to the law of students' development.

6. Preparation of teaching AIDS:

Computer equipment, teaching courseware, self-made activity corner, triangle, ruler, red scarf.

7. School preparation:

Self-made movable angle, triangle, ruler and irregular paper.

Second, teaching methods and learning methods:

This class uses the method of trial teaching and hands-on operation to stimulate students' interest in mathematics learning from curious and interesting things. In this process, students as the main body, under the guidance of teachers, learn knowledge, explore mathematical laws, develop thinking and cultivate innovative spirit. In teaching, teachers use modern teaching methods to make this course into vivid and novel multimedia courseware, and skillfully build a bridge of knowledge, so that students can actively explore and acquire new knowledge in the atmosphere of "entertaining".

Knowledge is important, but the process of seeking knowledge is more important; The result of trying is important, but the process of trying to solve the problem is more important. Therefore, in the guidance of learning methods, we should pay attention to the cultivation of students' observation, operation and classified thinking ability, and organize students' cooperative discussion so that they can inspire each other and communicate in many directions. We should give students as much time as possible to think, more space for activities, more opportunities to express themselves and more happiness to win.

Third, the teaching program design:

(1) Activity introduction:

Students, we will come into contact with all kinds of graphics every day in our lives. Do you know which figure? Put the picture and ask if there are any corners. Who wants to point up?

Intention: According to the characteristics of senior two students, let them participate in learning with curiosity and interest from the beginning, starting with the graphics they know and the existing experience and knowledge. At the same time, teachers use cooperative language to create a relaxed, democratic and flexible classroom atmosphere, which makes students feel happy and refreshed. This positive emotion can easily open the floodgates of thinking and sprout creativity.

(2) Import theme:

A preliminary understanding of the horn. What do you want to know after seeing this topic? Learn what?

Intention: Let students talk about their own requirements, set suspense, bring students into the realm of trying new knowledge, and keep students' attention focused on classroom teaching activities.

1. (test questions) Show me the true triangle, the red scarf and a book. Are there any corners in these figures? Who can point up and say, pay attention to guide the students to point at the right angle, and point at each other at the same table.

Intention: fully perceive the angle in practice, let students let go of their hands and feet as much as possible, and truly "fly high" their thinking, and fully mobilize their enthusiasm and autonomy in learning.

Fold the corner with your favorite round paper or irregular paper, find out where the corner is and feel what it feels like. Please find out the characteristics of the angle.

Intention: Children's wisdom comes from their fingertips. The excellent teaching plan of children's hands-on practice and operation participation adapts to children's activity age and psychological characteristics, and conforms to the law of children's understanding of things. Let the students fully perceive the connotation of the angle and describe the characteristics of the angle in language: the angle has a vertex and two sides, from which the language expression ability can be improved.

2. Show controversial attempts:

Show me the figure of the corner. Is this a corner?

Intention: "arouse interest with doubt and solve doubts with interest." With questions of doubt, they can be prompted to find out the rules and methods, so that students can feel the power of knowledge and enjoy the fun of learning.

3. Try to practice: judge whether the picture below is an angle? Why? (group discussion)

Intention: This set of tentative questions is not only a summary of the previous learning knowledge, but also a consolidation of the representation knowledge about angles. Try the steps of "classmate discussion" in teaching, mobilize everyone to speak actively, tell their own ideas and methods to solve problems, and let students "realize" the truth in the discussion, discover the means and methods to acquire knowledge, screen information from arguments, distinguish between true and false, and analyze right and wrong. It not only cultivates students' mathematical expression ability, but also cultivates their consciousness of active participation; It not only develops students' thinking, but also exerts the interaction between students.

4. Attempts to resolve disputes:

Intention: Students use their own knowledge to solve test questions, and at the same time form a clear representation of "what is a corner" in their minds, so as to deepen their understanding of the content of the textbook.

Please list which objects in life have horns.

Intention: From concrete to general, and from general to concrete, in this cycle, students have made a leap from perceptual data to rational understanding. In the speech expressing one's own views, knowledge has gained a deeper understanding.

Summary: In the first stage, students tried and explored in three aspects: thinking, doing and speaking, which made students have a deeper understanding of the teaching focus and improved their practical ability and language expression ability.

(3) The second attempt:

Are the angles of (1) and (2) the same? Please do something.

Intention: This is the difficulty of this lesson-what does the angle have to do with it? Let students come up with their own methods to judge and try, so as to find a good method, which provides students with sufficient opportunities to engage in mathematics activities. By thinking about various methods, they can form the habit of thinking and solving problems from different angles.

The teacher explained it and came to the conclusion that the size of the angle is related to the size of both sides, not to the length of both sides. Show the courseware and try to do the exercises. The angle between the hands on the clock face is changing. Please judge whether the angle is getting bigger or smaller.

Intention: Deepening the understanding of teaching difficulties is a process of guiding exploration and deep understanding. Organize and guide students to truly understand and master the "teaching difficulties" in independent exploration, cooperation and exchange, so that they can appreciate the victory in the attempt. Feel the joy of learning in front of a little sense of accomplishment.

2. Students teach themselves to draw a corner: After reading a book, students draw a corner with any shape they like best. Teachers and students discuss the amendment and then draw a corner.

Intention: The process of learning to draw corners is the last content of this lesson. Guide students to draw any corner, let them plug in the wings of imagination, and draw their most satisfactory corner with immature hands.

(4) the third attempt to practice:

1, count how many angles there are in each graph:

2. Use sticks (2 sticks) to place the figure and calculate the number of angles in the figure:

Intention: Hands-on practice is the main channel to cultivate students' innovative spirit. The first question is paving the way. The second question allows students to master the content of this lesson through posing and counting, and the innovative spirit is displayed in hands-on operation.

3. Development issues:

A square piece of paper, cut off one corner with scissors. There are still a few corners left in the group discussion. Try to cut them:

Intention: The design of the extension question embodies the whole content of teaching, and at the same time, it increases the content gradient, showing a ladder shape, which is a good extension question. Students' divergent thinking has been improved. In the process of cutting, spelling and counting, students' interest in learning is stimulated and the classroom atmosphere is activated. In communication and discussion, generate shows the spark of thinking.

Summary: Did you solve all your problems at the beginning of this class? Any other questions? What did you get from this lesson? (Students answer, the teacher summarizes)

Fourth, the blackboard design:

A corner has a vertex and two sides.

(2) The size of the angle is related to the size of both sides, but not to the length of both sides.

(3) Drawing corners: first point the vertices, then draw the edges, and fill in the corner markers.

Intention: Through blackboard writing, the important and difficult points of teaching are clearly presented to students. The overall design of blackboard writing is focused and scattered, which is beneficial to students to form a certain knowledge system.

Five, homework design:

After class, use three or four sticks to see how many shapes you can put and count how many corners each shape has.