In the recent open class for young teachers in our school, the course "Understanding Parallelogram and Trapezoid" taught by Mr. Dai was an impressive and successful math class. There are three reasons for this evaluation:
First, the introduction of new courses is closely combined with reality, which is impressive.
A wonderful beginning is half the battle. In order to arouse students' interest in learning, Mr. Dai started with familiar things around him and inspired students to think at the beginning of the class: Students, please observe carefully. What shapes are the objects in our school and classroom?
So, the students moved their eyes, hands, mouths and spoke enthusiastically. Some say there is a diamond on the retractable door at the school gate; Some say that the classroom blackboard is rectangular; Some people say that colored origami is square. At this time, Mr. Dai lost no time in showing a group of pictures with multimedia, abstracting perceptual objects into concrete graphics, and further asking: Please judge what shape the graphics on the screen are? Through the students' answers and discussions, we can all realize that rectangle, square, trapezoid, rhombus and parallelogram are all figures surrounded by four line segments, and the figure surrounded by four line segments is called quadrilateral.
Undoubtedly, through the introduction of this new course, students can not only quickly understand the definition of quadrangles, but also have a preliminary understanding that rectangles, squares, parallelograms and irregular quadrangles all belong to quadrangles, and unconsciously infiltrate the idea of set, laying the foundation for the following set diagram, which is ingenious, unique and impressive.
Second, let students experience and understand the definition and characteristics of parallelogram in the process of operation, and the teaching effect is remarkable.
The definition of parallelogram in the book is that two groups of parallelograms with parallel opposite sides are called parallelograms.
How to make students remember this definition firmly? Is it the student or the teacher? Reading textbooks or courseware? Teacher Dai doesn't need these options for the time being. Because, experience tells us that when you read on paper, you will soon forget, but when you do, you will really remember! Teacher Dai asked the students to measure whether the opposite sides of a parallelogram are parallel and equal with a ruler and a triangular ruler. Use a protractor to measure whether the diagonals of a parallelogram are equal.
Through these operations and experiences, students have experienced the whole process of acquiring knowledge. In this process, students not only gain knowledge, but also improve their skills, and their dominant position is fully guaranteed. So their conclusions about the definition and characteristics of parallelogram are undoubtedly profound and will be branded in their minds for a long time.
Third, the application of visual teaching AIDS and learning tools has played a role in making the finishing touch.
In this lesson, the instability of parallelogram is not only the focus of this section, but also the difficulty of this section. In order to highlight the key points and break through the difficulties, Mr. Dai asked everyone in the class to make an activity rectangular box. In class, she leads the students to pull the diagonal of the rectangular frame by hand, so that the students can witness the changing characteristics of the parallelogram with their own eyes, which is convenient for everyone to summarize the unstable and deformed characteristics of the parallelogram. This move has achieved twice the result with half the effort, which can be described as the finishing touch of teaching plan design.
To sum up, Dai's classroom structure is reasonable and the design is exquisite. Focusing on the definition and characteristics of parallelogram, the whole class organized questions and carried out operation experiments with clear objectives and prominent points, which fully embodied the new teaching concept of taking students as the main body, teachers as the leading factor, training as the main line and cultivating students' various abilities as the core, and achieved excellent results. Although the time is not properly arranged in the process of exploring the definition of trapezoid, this lesson is impressive and successful.