In the field of graphic geometry, the rich knowledge we learned in junior high school, such as graphic world, view projection, rotation, symmetry and circle correlation calculation, can develop students' spatial concept. The new curriculum standard points out: "The teaching of geometric knowledge should deepen the understanding of geometric shapes through practical activities such as observation, measurement and hands-on operation."

The following examples illustrate how I deal with and use this knowledge in my usual teaching:

First, cultivate students' intuitive thinking and develop the concept of space.

Intuitive thinking refers to a way of thinking that people can directly understand the essence of things without being bound by logical rules. This ability to react quickly, such as looking at the conditions of the topic or the graphics in the topic, and quickly saying its characteristics and implied meaning, is even more important in geometry learning.

1. According to students' psychological characteristics and cognitive rules, students should adopt intuitive means to gradually develop the concept of space in practice.

2. Design some simple imagination activities to deepen knowledge and cultivate students' spatial imagination ability.

3. Enrich students' mathematical language and develop students' spatial concept.

For example, I will talk about the calculation of a cone. Let the students use the triangle in their hands to rotate at right angles, see the three-dimensional figure formed by it from above, and then rotate on the hypotenuse as the axis to get what three-dimensional figure, so it is easy to form the three-dimensional figure of the cone in the students' minds. By making a cone model, students can know and understand the corresponding relationship between the cone and its development diagram, that is, the length of the generatrix of the cone is equal to the radius length of the sector, and the circumference of the bottom of the cone is equal to the arc length of the sector, which is beneficial to related calculation.

Second, train multiple solutions to one problem and develop the concept of space. Through several years of geometry teaching, I deeply realized that multiple solutions to a problem can not only develop students' intelligence from multiple angles, but also cultivate their spatial imagination.

Third, train each other to develop students' concept of space.

In the process of mutual transformation between "plane graphics" and "three-dimensional graphics", teachers need to guide students to observe the transformation results of graphics and make comparative thinking, find laws and methods. In teaching, let students "talk" and "pose" and realize that different three-dimensional graphics can abstract the same plane graphic, and the same plane graphic can put different three-dimensional graphics. This kind of interactive exercise is beneficial to cultivate students' spatial concept.

For example, display: four pyramids

1. Guide students to observe from the front, side and top, and say the plane figures they see respectively.

2. Let the students draw a plane figure on the blackboard from the front, side and top;

3. Observe and think in an orderly way:

In a word, if our teachers can handle it properly, it will undoubtedly have a certain transitional connection and enlightenment for students to learn solid geometry in senior high school in the future.