1. Describe the characteristics of rectangles and squares in your own language through operation, comparison and induction.

2. Further consolidate the understanding of the characteristics of rectangles and squares through activities such as making rectangles and squares.

3. Get the experience of learning graphics through activities such as "pull-pull".

[teaching material analysis]

The purpose of arranging the re-understanding of rectangle and square is to let students develop and try to summarize the characteristics of rectangle and square through hands-on operation and give play to their creativity. The textbook designs an inquiry activity to encourage students to explore the characteristics of rectangles and squares in operation, and then let students understand the relationship between rectangles and squares through thinking.

Analysis of the situation of schools and students

Students have intuitively known rectangles and squares in senior one, and this lesson should be further explored on this basis. According to the age characteristics of junior two students, I designed a series of activities, trying to make abstract knowledge lively, stimulate students' interest in learning and achieve better teaching results.

[Instructional design]

Preparation of learning tools: put an envelope of rectangular colored paper; Triangular ruler, ruler, scissors, etc. ; Many envelopes contain many rectangles, squares and fragments.

(a) review of imports

Teacher: Students, today the teacher brought you some friends you used to know. The courseware shows several squares and rectangles. Can you tell which are squares and which are rectangles?

It is easy to find. )

Teacher: We only knew these friends before. Do you want to know them better?

Health: Yes.

Teacher: Now let's study them deeply and compare who has the brightest eyes and who is most willing to use their brains.

(2) Independent exploration, cooperation and exchange.

The teacher gave each group an envelope with rectangles, squares and some fragments.

1. Explore their characteristics.

Teacher: Let's study the characteristics of rectangles and squares first. Study the method in the group first, and then operate.

Students' activities are very serious and enthusiastic, and teachers patrol and guide them. )

Teacher: Just now, the teacher found that the students studied very hard. I'm sure there will be results. Can we talk?

Health 1: Our group measured it with a ruler. The result of measurement is that the upper and lower sides of the rectangle are equal, the left and right sides are equal, and the four sides of the square are equal.

Teacher: The upper and lower sides of a rectangle are equal, and the left and right sides are equal. We can say ...

Health 2: The opposite sides of a rectangle are equal.

Teacher: You are really a thoughtful student.

S3: Our group adopted the method of "one fold, one fold".

Teacher: Can you demonstrate while talking?

Health 3: (loudly) Yes!

Health 3: First, fold the square in half along the diagonal line in the middle, and then fold it in half to find that all four sides of the square are equal. The rectangle is folded horizontally, overlapped up and down, folded vertically and overlapped left and right, indicating that the two opposite sides of the rectangle are equal respectively.

Teacher: Your method is really good. Which group has different methods?

Health 4: Xiaoxiao is measuring the angle with a triangular ruler. We also measured with a triangular ruler that the four corners of a rectangle and a square are right angles.

Teacher: Good! Just now, students have a better understanding of rectangles and squares through group cooperation, hands-on operation and careful observation. Look at the screen Can you replace it?

The courseware shows the content of "fill in", and the students fill in and say it out loud. )

In the reflection class, let the students choose their favorite methods for research. In this teaching link, there are both bilateral activities between teachers and students and exchanges between students; It is necessary to cooperate in groups and think independently, so that students can think and explore by themselves, which can greatly improve their learning enthusiasm and participation. )

play games

Teacher: Let's play a little game. Let's work together at the same table. One person will say the name of the figure, and another person will touch the figure in the envelope blindfolded, and then exchange tables.

Students play games in a relaxed and happy atmosphere. )

consolidate

Teacher: Students, we have learned the characteristics of rectangles and squares. Now, please make a rectangle and a square with some pieces.

(student production, teacher tour guidance. )

Teacher: Is everyone's work qualified? How do we test it?

Health 1: measure whether the four angles are right angles with a triangular ruler.

Health 2: I don't think it's necessary. Just give me a discount.

Health 3: (in a hurry) No, if the angle is not a right angle, you can't check it just by folding it.

Health 4: I don't think what they said is accurate. We should measure and discount. Measure the angle and fold the hem.

Teacher: Can you demonstrate it?

(Students demonstrate on the stage. )

Teacher: Great! Students can make rectangles and squares by using their characteristics. What is the relationship between them?

(Reflection and consolidation exercises, based on the foundation, and strive for change. Through games and small-scale production, students can internalize new knowledge in creative practice, cultivate space concept and innovative consciousness, and let students at different levels gain something. )

4. Explore the relationship between them

Teacher: There is a piece of colored paper in this envelope. Can you guess what shape?

Health: rectangle, square, triangle, ...

Teacher: What shape is it? Students, please observe carefully.

(The teacher pulls out some colored paper. The impatient classmate shouted: rectangle. Keep pulling. )

Health: Rectangular and square. (The voice is different. )

The teacher continued to pull slowly, and the students' answers hovered between rectangles and squares. The teacher pulled out all the colored paper. )

Health: (Shouting in unison) Rectangular.

Teacher: The students watched carefully. The teacher has a question for you: What did you find from the teacher's pulling just now?

Health: There are squares in the rectangle.

Health: No! There is a rectangle in the square.

Health: No! There are squares in the rectangle.

(The students argue. )

Teacher: Students, think about it. The characteristics of rectangle are ...

Health: The opposing sides are equal.

Teacher: So, are the two sides of the square equal?

(Student thoughtfully: Yes. )

Teacher: So, we can say that a square is a special rectangle.

(The student suddenly realized. )

(Reflection) Exploring the relationship between rectangle and square through vivid and simple games will help students feel the inner connection between graphics and have an intuitive understanding of plane graphics. )

(3) Summary

Teacher: What have you gained from learning this lesson? What do you think is the most interesting part of this class? Talk to your deskmate.

Students can speak freely and express their understanding and feelings. )

Teaching reflection

1. Attach importance to students' practical ability.

In teaching, I pay attention to let students get an intuitive experience of plane graphics in activities such as observation and operation. I make full use of the opportunities provided by textbooks to organize teaching activities, so that students can fully practice in mathematics activities and encourage students to learn.

2. Cultivate students' ability of independent exploration, cooperation and communication.

In teaching, teachers attach importance to students' learning process, make full use of dynamic learning materials, carefully organize, let students explore independently, cooperate and communicate, give full play to each student's enthusiasm, let each student move in an exciting and happy atmosphere, and improve learning efficiency.

3. Lack and confusion

(1) In class, students' mathematical language is not standardized enough, and teachers fail to correct and explain it in time. Does the teacher need to tell the second grade students? For example, in this class, students say that the diagonal line is inclined in the middle. This is a question that needs to be considered.

(2) For the students' wonderful performance, the teacher failed to give an encouraging evaluation in time, but only tasted it.

(3) This course is suitable for students to explore and operate independently, but it will achieve the teaching purpose if it is operated for a long time. If it is not handled well, it will be counterproductive. How to grasp, I have been thinking.

[Case Review]

In this course, students do it through a lot of hands-on activities, in which students feel and experience themselves. Teachers can fully provide opportunities for students to have a sense of accomplishment in heated discussions and bold reports. Students' personal experience in the activities makes the classroom truly active and independent, which effectively changes the disadvantages of traditional teaching methods and learning methods that force students' thinking into the preset track and limit students' thinking space. The learning process has really become a process of teacher-student interaction, which has cultivated students' ability of independent inquiry and cooperative learning, and achieved good results in the formation of mathematical knowledge and skills, the development of emotional attitude and the cultivation of thinking ability.