The classification of horns is a lesson in primary schools! The following is a sample of classified lecture notes about angles that I have compiled for you. I hope you like it!

First, teaching material analysis:

The content of the class I am talking about is the compulsory education curriculum standard experimental textbook "The Classification of Corners" in Unit 2, Volume 3, Volume 1, People's Education Press. This part is based on the students' preliminary understanding of the angle, and the angle can be measured with a protractor. The textbook uses the real materials of two folding fans to understand straight corners and rounded corners. Through observation, hands-on practice and exploration, students can master the relationship among acute angle, right angle, obtuse angle, straight angle and rounded corner, so as to feel that the content of mathematics learning is realistic and meaningful. So as to experience the fun of "learning mathematics" and "doing mathematics". Based on the above understanding of the textbook, according to the mathematics curriculum standards, the following teaching objectives are determined.

Second, the teaching objectives:

Knowledge goal: to know boxers and rounded corners. Grasp the relationship among acute angle, obtuse angle, right angle, right angle and fillet through observation.

Ability goal: to cultivate students' ability of observation, comparison and abstraction through vivid and interesting mathematical situations and activities.

Emotional goal: let students experience the exploration process of classification. Experience the fun of cooperation and communication with others, learn to find problems with a mathematical eye, and cultivate the concept of space.

Teaching emphasis: understand the straight angle and rounded corner, and master the relationship between acute angle, right angle, obtuse angle, straight angle and rounded corner.

Teaching difficulty: understanding rounded corners.

Third, the teaching design:

Zankov, a psychologist in the former Soviet Union, said, "Without real curiosity and interest, what you have learned will easily evaporate from your memory."

Curriculum Standard also points out that mathematics teaching should be closely linked with students' real life, and based on students' cognitive level and existing experience, vivid and interesting situations should be created to stimulate students' interest. According to the concept of the new curriculum, this class is conducted by hands-on practice, independent exploration and cooperation. The specific teaching design is as follows:

1, Creating a Situation and Stimulating Interest:

Confucius said, "Knowing is not as good as being kind, and being kind is not as good as being happy." For students, mathematics learning should be lively and interesting. So I started from solve riddles on the lanterns, and let students take the initiative to participate in activities.

Students, do you like guessing riddles? Then I will test you. "When you have something in your hand, there is no wind moving, no wind moving, and there is wind moving. In summer, it shook Tao Tao. " Hit-daily necessities. At this time, students' interest is high. I said gyro, some people said windmill, some people said fan. By the way, fans.

The teacher also brought a fan today! At this time, I show three pictures and have a look. What angles are they? Please look at the big screen.

The design of this link enables students to experience the close relationship between mathematics and daily life, pay moderate attention to students' life experience and existing knowledge, and also pave the way for the follow-up study of this class.

2, demonstration operation, clear concept:

Students, this folding fan has a special angle besides the acute angle, obtuse angle and right angle just found. Courseware demonstration: form a right angle, and then abstract a graphic demonstration. Ask the students to describe the formation of right angles, and then perform the drawing of right angles. )

Now the teacher has brought a fan to the students. The courseware demonstrates the formation of rounded corners, and then abstracts the graphics. Where are the vertices and sides of the fillet? (Play the picture of rounded corners)

The design of this link can combine abstract mathematical knowledge with concrete objects, turn abstract into concrete, and turn difficult into easy.

Activity 1: Hands-on Practice and Understanding Mathematics

Piaget believes that the most fundamental way for children to learn should be activity, which is the basis of understanding, so I provide students with the opportunity to operate.

First of all, start the operation and feel the concepts of boxer and fillet from the perspective of activity.

Then start the operation and study the degree of straight angle and rounded corner.

In this link, students explore and practice in their favorite way, paving the way for the classification of learning angles.

Activity 2: Work in groups and explore classification.

Curriculum standards point out that mathematics teaching activities should stimulate students' enthusiasm for learning and provide them with opportunities to fully engage in mathematics activities. Help them truly understand the knowledge and skills of mathematics, the ideas and methods of mathematics in the process of independent exploration and cooperation and communication. Therefore, I designed this question: the teacher prepares a wanbao bag for each group. Go and see what's inside. Please measure the degree of the angle in your favorite way and indicate the degree. The group will study how to classify them.

Then both teachers and students come to the conclusion that the acute angle is less than 90.

A right angle equals 90 degrees.

The obtuse angle is greater than 90 and less than 180.

The flat angle is equal to 180.

The fillet is equal to 360 degrees.

Students, through the operation just now, have you found the relationship between right angles, right angles and rounded corners? The students' spirits rose again. They raised their hands and said:

1 right angle =2 right angles

One fillet =2 right angles =4 right angles.

This link aims to further deepen students' understanding of diagonal lines and improve their skills in measuring angles. Then give play to the advantages of group cooperation. It cultivates students' sense of cooperation and provides them with a good opportunity to experience the process of exploring and solving problems.

3. Classroom exercises:

(1) Line by line: (Understand the orderly arrangement of five corners)

() Angle

(2) Among the angles 46, 130, 90, 270, 25, 107, 180, 360, () is acute, () is right, () is obtuse, () is right and () is rounded.

(3) When the clock is at ten o'clock, the hour hand and the minute hand form an angle of () degrees.

4. Fold a round piece of paper in half for three times, and then unfold it. What angle can you get?

In this class, I designed five exercises, the contents of which are from simple to deep, and gradually improved, so that students can feel the sense of success in solving practical problems with mathematical knowledge, and provide students with time and space for independent exploration, thus generating positive mathematical feelings.

In short, in this class, I take interest as the guide, activity as the carrier, and three-dimensional goals as the purpose, so that students can experience practical activities of observation, operation, experiment and reasoning, and enjoy the fun of mathematics learning in a pleasant atmosphere.

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