Main teaching contents: graphic transformation, factor and multiple, cuboid and cube, meaning and nature of fraction, addition and subtraction of fraction, wide angle and comprehensive application of statistics and mathematics, etc. Key and difficult points in the second volume of grade five:

1. Graphic conversion. Focus on mastering the symmetry axis of general geometric figures, understand the rotation of figures, explore the characteristics and properties of figure rotation, and rotate simple figures 90 degrees on square paper.

2. Factors and multiples. Make students master the concepts of factor, multiple, prime number and composite number, and know the connections and differences between related concepts. Master the characteristics of multiples of 2, 5 and 3. There are many concepts, so we should clarify the relationship between them, not memorize them by rote, master them on the basis of understanding, and learn to use them flexibly. Number theory itself is a subject that studies the properties of integers, and sometimes it is not easy to combine with specific situations, such as concepts such as prime numbers and composite numbers, and it is difficult to introduce them from real life. In the fifth grade, students' abstract ability has been further developed, and it is necessary to consciously cultivate their abstract generalization ability.

3. Cubes and cubes. Grasp the characteristics of cuboids and cubes, master the formulas of cuboids and cubes' volume and surface area, explore some measurement methods of physical volume, and promote the further development of students' space concept. This part is the most difficult, because the rational concept of space has just begun to form. Suggestion: (1) The knowledge learned is closely related to real life. An object that combines physical concepts in everyday life. Such as the vertex, edge, surface, surface area, volume, volume and so on. Like a matchbox. (2) Strengthen hands-on practice and independent exploration, so that students can experience the formation process of knowledge. Like making cartons.

4. The significance and nature of music score. This is the transformation of students from intuitive mathematics to abstract mathematics, and perceptual knowledge rises to rational knowledge. Summarize the meaning of fraction, deepen the understanding of the meaning of fraction from the aspects of the generation of fraction, the relationship between fraction and division, and then learn and understand the basic concepts related to fraction, and master the necessary skills such as reduction, universal fraction and reciprocity between fraction and decimal. In order to cultivate students' sense of numbers, I will ask them to memorize commonly used fractions and decimals. Such as 24X0.875 These knowledge will be used in the systematic study of the following four fractional operations and their applications. Therefore, learning the content of this unit well is the necessary basis for mastering the four operations of fractions and learning to apply the knowledge of fractions to solve a series of practical problems.

5. Addition and subtraction of fractions. Relatively simple. This unit is one of the important basic knowledge of mathematical operation. Mastering the calculation method of fractional addition and subtraction is an important measure to evaluate whether students have good calculation ability and sense of numbers.

6. statistics. Understand the meaning of mode, learn to find the mode of a set of data, and understand the statistical significance of mode. According to the specific situation of the data, choose appropriate statistics to represent the different characteristics of the data.

7. Mathematical wide angle. Guide students to infiltrate optimized mathematical thinking methods into students through activities such as observation, guessing, experiment and reasoning, so as to realize the diversity of problem-solving strategies and the effectiveness of using optimized methods to solve problems and feel the charm of mathematics.