Last week and this week, I listened to two new graphics classes, one is the area of parallelogram in grade five, and the other is the circumference of grade six. These two courses are based on students' understanding of the shapes, characteristics and names of various parts of graphics. However, students are not familiar with how to calculate their perimeter or area, and their understanding of graphics is not deep enough to directly infer the area. Therefore, if students want to understand how to calculate the perimeter and area of a graph, they must combine the graph knowledge they have learned in the past, let them find the similarities between the old and new graphs from the past knowledge framework, and transfer their knowledge by using the transformed mathematical ideas.

There is a very typical transformation idea in the lesson "the area of parallelogram". The teacher began by asking students to study the parking prices of rectangles and parallelograms. He first used the method of tiling small squares, then counted the squares, and then let the students intuitively understand how the parallelogram was transformed into a rectangle by cutting and spelling.

On the circumference, students also need to change their way of thinking by changing their thinking in order to solve the problem. The shape of a circle is a curve, which can't be measured directly with learning tools known to students, such as a ruler. We can only try to transform the curve into a straight line with tools and then measure it. In the process of inquiry, students found that the circumference can be transformed into the length of rope or ruler by rolling and winding, and then measured.

? Transformation thought is an extremely important part of mathematical thought, but it is difficult for students to understand the transformation process. In the course of listening to the class, I found that in order to let students fully understand how to solve problems by using transformation ideas, we need to do the following:

? 1. Students must feel the process of graphic transformation through cooperative inquiry activities, and the steps of hands-on operation are far from being replaced by listening, watching and thinking.

? 2. When assigning a group to explore the task, the teacher must be clear about what the task needs to achieve, how the group divides the work, and clearly inform the students.

? Students can't find a way to transform themselves from the beginning. Teachers must give hints to guide students. They don't say too much, just tell the children the way. Instead, they can remind students what learning tools they can use to help them. Can't say too little, as long as the result of the task, regardless of the process of the task, the process of how students get the result is the most important link in this class.

Changing ideas is not what teachers tell students to learn. It takes a practical process for students to learn a mathematical idea from textbook knowledge. Only when students really understand this mathematical idea can it react to their future study and life.