Teaching objective: 1. Through examples in life, let students feel the common rotation phenomenon in life.

2. Cultivate students' practical ability through their rotation experience.

3. Cultivate students' awareness of applied mathematics.

Emphasis and difficulty of teaching: perceptual rotation

Teaching process:

First, experience feelings.

1. Observe rotating objects, such as electric fans and windmills.

Please show how they move with your hands.

3. Are there any sports like this in your life? Please give an example.

What do we call a phenomenon like this?

Judge: which objects belong to rotation.

Second, feel the direction of rotation.

1. Show two objects rotating in different directions for students to classify.

2. Why do you want to divide it like this?

3. Show the clock face and let the students observe how the second hand turns.

4. Give the rotation a name according to different rotation directions.

Summary: This rotation from left to right like a second hand is called clockwise rotation, and the opposite rotation is called counterclockwise rotation.

Third, do it.

1, complete the third question on page 43.

2. Make a rotation by yourself. Let what you have spin.

3. Turn in different directions as instructed.

4. Finish page 42 of the textbook, and then do it.

Fourth, show the beauty of rotation and create the beauty of rotation

1. Show the picture of Bauhinia, and let the students think about how it was created.

2. Use rotation to create beautiful patterns.

Class summary

Model essay on the second volume of mathematics teaching plan in the second grade of primary school

Teaching content of acute angle and obtuse angle: the content on pages 38-39 of the textbook.

Teaching objectives:

1, to further consolidate students' understanding of "angle", "edge", "vertex" and "right angle" and to be familiar with the size of comparative angle. Try to make students compare sizes in various ways.

2. Introduction of new lessons. In the comparison, it is put forward that one angle is larger than the right angle and the other angle is smaller than the right angle, thus revealing the concepts of acute angle and obtuse angle. The leading idea is to exert students' innovative ability. When drawing a picture on the blackboard, students should read it to deepen their understanding of acute angle and obtuse angle.

3, practice, pay attention to the formation process of students' knowledge, from judgment and reasoning, discovery and discovery to the practice of drawing, spelling and folding in group cooperation, while fully demonstrating students' advantages, pay attention to the cultivation of students' hands-on operation ability and cooperative spirit. In the process of cooperation, examine the reasonable overall planning of students' tasks and time.

4. The whole process reflects students' interest in learning and exploring in activities. Fully embody life mathematics and happy mathematics.

Teaching focus:

1, know acute angle and obtuse angle, and understand the relationship with right angle.

2. On the basis of understanding, you can correctly fold or draw acute and obtuse angles.

3, around life, through the way of competition, consolidate the understanding of acute angle and obtuse angle.

Teaching aid preparation: triangular ruler, paper

Prepare learning tools: triangular ruler and paper for students.

Teaching process:

First, guide the class and review the old knowledge.

1, review the content. Guide students to recall the knowledge about angles.

Show me the horn. According to legend, this is an angle.

How are horns made? Please fill in "Edge", "Vertex" and "Edge" on the map.

Show me the right angle. What is this? (right angle)

What else do you know besides these? Group discussion report

2. Compare the sizes of the two corners.

Two groups: one group is completely coincident after moving, that is, equal; A group cannot completely overlap after moving, that is, inequality. The second group can ask students to point out which angle is larger and which angle is smaller. )

3. Compare the size of acute angle and obtuse angle (note that the concept of two angles is not revealed here, but only appears as two ordinary angles). Complete the comparison with a right angle method.

Second, explore independently and introduce new knowledge into learning.

1. Show me the site map of Shanghai Yangpu Bridge. Please observe carefully. Can you find the corner in this painting? Tell me where it is.

2. Further deepen the understanding of new knowledge through recollection. And write on the blackboard.

① One is an acute angle and the other is an obtuse angle. (blackboard writing "acute angle" and "obtuse angle")

② Talk about the relationship between acute angle and right angle. (Write acute angle "less than right angle" under the blackboard); Recall the relationship between obtuse angle and right angle. (Below the obtuse angle, the blackboard says "greater than right angle")

According to the learned method, please make two right angles above the words "acute angle" and "obtuse angle" respectively.

According to the concept, draw an acute angle on one right angle and an obtuse angle on the other right angle with pens of different colors. Deepen the understanding of acute angle and obtuse angle.

⑤ Read and deepen your memory. Draw an acute angle and an obtuse angle in the exercise book for the teacher to patrol.

6. Answer first. The teacher asked questions according to the different concepts of acute angle and obtuse angle. Active classroom atmosphere.

Example: A. The acute angle is greater than the right angle ()

B, bigger than the right angle is ()

Third, consolidate the practical stage, combine mathematics knowledge with life, implement group activity teaching, and complete it in cooperation.

1, guiding students to operate.

(1) Please make a right angle with the paper prepared in advance.

(2) Please make an acute angle and an obtuse angle.

(3) Please draw an acute angle, an obtuse angle and a right angle with a ruler and a triangle respectively.

2, free activities: find it!

The teacher took me to the little turtle's house. Look! The little turtle's home is made up of figures we have studied, including acute angle, obtuse angle and right angle. Look carefully, children. Which angles are right angles? Which angles are acute? Which angles are obtuse? Tell me why.

3. Show two true and false questions: (the method of courseware comparison)

A. which angles are acute in the picture below? B which angles in the picture below are obtuse?

4. A square treasure box with "Zui" written on it.

Show me two parts. (Courseware board performance)

A, use angle to describe graphics. For example, a red scarf consists of two () and 1 ().

Describe the things in the classroom in the same way. The blackboard is made up of four right angles. (The group is free to speak, and the speaking time limit is 1 minute)

5, teamwork to complete three parts, limited time. Pay attention to students' sense of cooperation and plan tasks and time reasonably.

A, spell it. Gather the triangular rulers of all the children in the group and spell out acute angles and obtuse angles of different sizes.

B.draw a picture. Draw an acute angle and an obtuse angle with a fixed point as the vertex,

C, give me a discount. Fold this paper into acute and obtuse angles.

Fourth, summarize the deepening stage.

Explain in the group what kind of angle is an acute angle? What is the obtuse angle?

2 Experience, when we do morning exercises, we often have arm movements. Think about how far your arm extends, when it is acute, when it is obtuse and when it is right.

Model essay on the second volume of mathematics teaching plan in the second grade of the third primary school

Average teaching content: textbook P 13 ~ 14, and corresponding exercises in example 1, example 2 and exercise 3.

Teaching objectives:

1. Establish the concept of "average score" in specific situations and practical activities.

2. Let students fully experience the process of "average score" and make clear the meaning of "average score". Initially formed the appearance of "average score".

3. Guide students to feel the connection between "average score" and real life, and cultivate students' inquiry consciousness and problem-solving ability.

Teaching emphasis: understand and master the meaning and method of average score.

Teaching difficulty: mastering the method of average score.

Teaching preparation: several kinds of food, physical projection, etc.

Teaching process:

First, create a situation and feel the "average score"

1, session import, actual operation

(1) It's spring, and the teacher in bright primary school decided to take her classmates for a spring outing. They want to distribute some food. Brought you a present. ) The teacher will give it to you today. Ask the group leader to receive the gift (12 candy). The students used their brains to find ways to distribute candy to every student in the group and ask for all the candy. (and every student is required to be satisfied)

(2) Hands-on operation of each group

(3) Each group reports the situation and the teacher writes it on the blackboard.

Step 2 observe the problem

(1) Please observe the results of each group. What did you find?

(2) student observation report.

(3) From the observation, we found that some components have the same amount. Can you give such a division a proper name?

(4) Students name themselves.

Step 3 show the theme

(1) The children have good names. In mathematics, we call the same number of points in each part the average score.

(blackboard writing topic)

(2) What is the average score?

(3) How to make it average?

(4) Students exchange reports.

Second, practice and learn the average score.

1, Teaching Example 2: Divide 15 oranges into 5 parts on average. How to divide it? How many points?

(1).

(2) Each team scores one point.

(3) the way students report.

(4) What kind of division do you like? Why?

2. Divide one point: divide eight sticks into four parts on average. How many sticks should there be in each part? (Students get one point for starting work)

3. Finish the homework on page 14 of the textbook and divide 12 bottles of mineral water into three parts on average.

Let the students circle their own opinions. )

Third, application expansion, understanding the average score

1, exercise 3, question 2.

(1) It is certain that the second division conforms to the meaning of the topic.

(2) Guide students to observe whether the third score is average. What should be done to make it conform to the meaning of the question?

(3) Students communicate, discuss and report.

2. Practical activities: flower arranging activities.

3. List examples of average scores in life.

Fourth, experience success and have an average aftertaste.

What do you feel and gain after learning this lesson?

Teaching reflection: Students initially perceive the meaning of the average score, and will use different methods to average the score.