Teaching content: Jiangsu Education Press, new curriculum standard for compulsory education, mathematics textbook for second grade primary school, Volume IV, 68~7 1.

Teaching objective: 1. Knowing the angle according to the life situation and knowing the names of each part of the angle, we will use different methods and materials to make the angle.

2. Experience the perception of the angle in the operation activities. We will compare the angle in various ways and develop our mathematical thinking ability in the process of exploring the comparison of the angle.

3. In the process of creatively using tools and materials to make corners and compare the sizes of corners, experience the diversity of problem-solving strategies and cultivate students' practical ability and innovative consciousness.

Teaching emphasis: the shape of angle in abstract intuition.

Difficulties in teaching: the understanding angle is related to the degree of differences between the two sides, and various methods are explored to compare the angle.

Preparation of teaching AIDS: multimedia courseware, wooden sticks, two pieces of hard paper, round handmade paper and a wool.

Main teaching ideas and selected teaching methods:

Operation and thinking are inseparable, operation is the premise and thinking is the key. In this class, students are encouraged to think and communicate through activities such as "watching, watching, doing and comparing". In the activity, teachers boldly let go and adopt the learning mode of group cooperation and independent inquiry to guide students to explore independently. While exploring knowledge, it not only deepens students' diagonal understanding, but also enriches the experience of mathematical activities. Through interesting inquiry activities, students have tasted the success and joy of independent, cooperative and inquiry learning, and their self-confidence and sense of accomplishment have also been enhanced.

Teaching process:

First, create situations and introduce new lessons.

1, story import

Dialogue: There are a group of lovely graphic dolls living in the kingdom of mathematics. They are happy to sing, dance and play games together all day! Among them, "horn" doll is the most naughty. It is true that when the graphic dolls are playing hide-and-seek games, the "horn" dolls are hidden in some objects in our lives. Can you find it?

Step 2 reveal the topic

Today, in this class, let's find the "horn" doll and make friends with "horn", shall we?

[Teaching assumption: This link creates a story situation that students like, stimulates students' interest in learning, guides students to further explore learning, and helps students find the connection between life and new knowledge, that is, the hidden corner in the graph. ]

Second, the operation time perception, independent construction

1, abstract angle, and know the names of each part of the angle.

(1) From the angle of physical object induction

(Showing multimedia pictures) There are naughty baby horns hidden in these objects. Can you find them? Bibi, whose eyes are the brightest.

Who can tell me where you found the horn? Guide students to find the angles and points on the surface of objects.

(2) abstract angle

The teacher also found some angles from these objects and drew them. Point out: Figures like this are all angles.

[Teaching Assumption: Make full use of students' existing life experience, let students find the corners in real objects, and abstract the corner graphics on the basis of students' intuitive understanding]

2. Know the names of each part of the angle.

(1) Please poke your palm with a sharp place. How do you feel? Touch its two lines again (pointy). How do you feel? (straight)

(2) Do you know what this sharp place and straight line are called? They are hidden on page 68 of the math book. Go find them.

(3) Summary: A corner has a vertex and two sides.

[Teaching Assumption: Make full use of students' existing life experience, from observing physical objects to abstract corners, and know all parts of corners. This link is from intuitive image to abstraction, which helps students to deeply establish the appearance of corners under the support of heavy perceptual experience, conforms to children's thinking characteristics, and contains the concept that "mathematics comes from life". ]

(4) Can you point out the vertices and sides of these angles?

3, judge the contrast, deepen the appearance

Dialogue: I heard that we were in the corner, and several small guests came to the class, all vying to say that they were the corner. Who can judge?

(1) Can you point out which of these figures are corners? Aren't those horns?

(2) Corners are hidden in every corner of our lives. Find out what other objects around us have horns on their surfaces.

Teaching assumption: abstract the corner graphics and guide students back to the life situation, enrich the accumulation of diagonal representations in the process of finding corners, and let students further feel the close connection between mathematics and daily life.

4. Make an angle, and the perception angle has a size.

(1) Trial operation and practical experience.

Dialogue: horns can be seen everywhere in our lives. Do you want to do it yourself? Give it a try!

The teacher has prepared some materials for you (two sticks, two pieces of hard paper, a wool and a round paper). Please create a corner according to your own needs, using the materials provided by the teacher or the objects around you, and compare which group has come up with more methods. (Teamwork, teacher patrol) (2) Performance display-group, who will introduce your corner? (Displays the angle formed by the physical projection.

(3) The perception angle is different.

Teacher: The children have a pair of skillful hands that can make various angles, and the teacher also makes an angle. Will the teacher's angle change? Can you make this angle larger or smaller? How to make the angle bigger? Smaller?

(4) From here, we can find out what is needed to enlarge the angle. Make the angle smaller, just what? So, what does the angle matter?

[Teaching hypothesis: "After listening, you will forget; After reading it, you remember it; After doing it, you will really master it. " Through personal operation, students gain their own experience in exploring mathematics and cultivate their own exploration consciousness. Make corners and display corners in groups, so that students can participate in cooperation and exchange activities. During the communication, the students realized that there are many ways to make corners, and initially experienced the diversity of problem-solving strategies. ]

5. Compare the angles.

Q: Can you compare the sizes of horns now?

(1) direct comparison, guiding observation.

There are four clock faces. The hour hand and the minute hand form different angles. Can you see which angle is the biggest? Which angle is the smallest?

(2) Self-inquiry and induced thinking

Q: Who is the bigger of the remaining two corners? Can you find a way to compare their sizes?

(3) Discuss with the children at the same table.

(4) Do you know other ways to compare angles?

Teacher: Boy, it's amazing to think of so many ways to compare angles.

[Teaching assumption: Under the guidance of teachers, students fully cooperate and learn from each other's strengths. The way students communicate on the stage not only exercises their oral expression ability, but also gains a successful experience with the affirmation of teachers and classmates, paying attention to students' emotions, attitudes and values]

Third, comprehensive utilization, consolidation and deepening.

Teacher: Horn dolls are really naughty. Now it has been hidden in the children's textbooks. Can you find them?

1, "Think about it and do it" 3 questions

(1) Complete independently and communicate collectively.

(2) guiding thinking. Think according to the numbers you see and the answers you fill in. What did you find? Can you infer how many sides and angles a triangle has based on your own findings?

2. "Think and act" 2

Complete independently and communicate collectively.

3. Show me Zhiduoxing. Do you know how many angles there are on this star?

Fourth, class summary, expansion and extension.

1, pass this lesson? What have you gained?

2. Jiao You is very happy to see the children so smart. I want to give you a pair of gold scissors. Please go home and try to cut a corner of a rectangular piece of paper. Let's see how many corners are left. Let's see who has more wounds, shall we?

[Design intent]

1, pay attention to the age characteristics of students, create situations, and let students have the desire to explore. At the beginning of teaching, we introduce new lessons with story situations that junior children are interested in, and hide the problems in the situations, so that students feel lively and interesting and have the desire to explore. Through the creation of situations, students learn knowledge in a pleasant atmosphere, create a good classroom atmosphere, and make the whole classroom full of vitality.

2. Pay attention to hands-on operation, independent exploration and cooperation, so that students can experience the process of inquiry. In this lesson, teachers should pay attention to connecting students' life experience and activity experience, and guide students to actively participate in and experience the process of knowledge formation and exploration. First of all, pay attention to creating a space for students to explore independently. Under the coordination of various senses, students have a preliminary understanding of the angle through touching, seeing, watching and doing. Secondly, we focus on promoting cooperation and exchanges. Students can realize the diversity of problem-solving strategies through group discussion and class communication, which not only protects students' thinking of seeking differences, but also deepens their diagonal understanding in communication.