Today, I said the topic of the class is "Cubic Root". This lesson is the content of the first lesson in Chapter 10, Section 6.

The operation of finding the square root and cube root of a number is one of the basic operations in mathematics, which is often used in radical operation, equation solving and geometric figure solving. The significance of learning cube root lies in: (1) It has a wide range of applications, because all spatial forms are three-dimensional, and the calculation of related volume often involves the square root. (2) Cubic root is a special case of odd root, just as square root is a special case of even power, so it is of typical significance to further study the properties of odd root.

Teaching objective: 1. Be able to define square roots and square roots, and remember the different conclusions of positive, zero and negative cubic roots; The cube root of A can be represented by symbols, and the number and index of the roots can be pointed out, so that the symbols can be read correctly, and the publisher and cube are reciprocal operations. 2. According to the definition of cube root, the cube root of a complete cube can be found. The focus of teaching is to understand and solve the related concepts of cube root. Highlight the contrast between cube root and square root in teaching, and find out the difference and connection between them. This not only consolidates the concept of square root, but also helps to deepen the understanding of cubic root.

In the process of teaching, I pay attention to the guiding role of teachers and the main position of students. This section is the study of new lesson content. In the teaching process, we strive to guide students to become knowledge discoverers, combine teachers' guidance with students' problem solving, and create situations for students.

In the introduction of the class, a practical application problem of finding cubic roots is adopted. When the volume is known, the side length of the cube can be found. Practical application problems are easy for students to accept. Then review the similar operation-square root, which has been learned, and lay the foundation for the next comparison with cubic root. In order to cultivate students' autonomous learning ability, I gave them questions and asked them to read books with them. Find out the basic concept of cube root by yourself. The discussion about the number of cubic roots is the difficulty in this section. Considering that this conclusion is different from the corresponding conclusion of square root, this paper uses the method of inspiring students to think first, puts forward the thinking problem about the number of positive, zero and negative cubic roots through "thinking", and then arranges examples to find the cubic roots of some specific numbers. After students think and have some perceptual knowledge, they sum up their own conclusions. Then, guide students to sum up the difference between square root and cube root, and emphasize that the root sign can not be omitted when expressing cube root with the root sign formula; And the uniqueness of cubic roots. Considering that if the teaching plan is completed ahead of schedule, in addition to the exercise paper, I have prepared some confusing propositions for students to judge and distinguish, so as to consolidate the knowledge they have learned.

This part will be completed in two class hours. In the second class, we will further study the cubic root in solving equations and its comprehensive application with the square root part.

There are still many shortcomings in this class. I hope you can give me your opinions!