The teaching contents, objectives, explanations and suggestions of the eighth volume of primary school mathematics published by People's Education Press: 1, four operations, two positions and directions, three algorithms and simple calculations, the meaning and nature of four decimals in nutritious lunch, five addition and subtraction of six decimals in triangle, seven statistics, eight wide-angle mathematics stewards, nine review of the teaching objectives of Unit 1, four operations, 1. 2. Let students experience the process of exploring and communicating to solve practical problems, feel some strategies and methods to solve problems, and learn to solve some practical problems through two or three steps of calculation. 3. In the process of solving practical problems, make students develop study habits such as careful examination of questions and independent thinking. Explanation and suggestion 1. This unit mainly teaches and combs the order of mixed operations. In front of the mixed operation, the students have learned to calculate the two-step problem from left to right and know the function of brackets. Here, we mainly teach the operation order including two-level operation, and sort out the order of mixed operation. The main contents include: sorting out the order of operations at the same level (example 1 mixed operation, example 2 mixed operation of multiplication and division), teaching and sorting out the order of two-level operations (example 3 mixed operation of sum (difference) of product quotient, mixed operation of sum (difference) of two quotients) and bracketed operation order (example 5 three-step operation problem with brackets), and operation about 0. 2. Solving problems and sorting out the order of elementary arithmetic are organically combined. This unit combines solving problems when sorting out the order of mixed operations. The purpose is to enable students to further master the strategies and methods of analyzing and solving problems in the process of solving practical problems, and at the same time understand the necessity of specifying the operation order, so as to systematically master the order of mixed operations. 3. organically combine the process of exploring problem-solving ideas with the understanding of operation order. This unit is to make students feel the necessity of specifying the order of mixed operations and master the order of mixed operations in the process of solving problems. Therefore, in teaching, we should make full use of the vivid situations provided by textbooks, let students think and explore independently, and form steps and methods to solve problems on the basis of cooperation and communication. What do we need first? What method is used to calculate? What else do you want? What method is used to calculate? What do you want in the end? What method is used to calculate? Combine the steps of solving problems with the order of operation. When enumerating comprehensive formulas, students should also ask about the basis and practical significance of each step of the formula, so as to promote students to correctly summarize the operation order of mixed operations. 4. Help students master the steps and strategies of solving problems step by step. The order of mixed operation in this unit is combined with problem solving, and the steps and strategies of problem solving are one of the key and difficult points. In teaching, we should pay attention to strengthening the analysis of quantity relationship, and guide students to describe problem-solving ideas through the relationship between quantity and dosage when describing problem-solving ideas. For example, students can be guided to describe their thinking like this: "First calculate how many people will be received every day, and then calculate how many people will be received in six days". Don't stop at the description of "first use 987÷3, then multiply it by 6". Students may not be used to it at first, but they should gradually cultivate this analytical method. Unit 2 Position and Direction Teaching Objectives 1. By solving practical problems, students can understand the application of positioning in life and the methods of positioning. 2. Enable students to determine the position of objects according to the direction and distance, and describe a simple road map. Explanations and suggestions 1, this unit * * * arranged four examples: Example 1 Determine the position of an object according to the two conditions of direction and distance Example 2 Draw the position of an object on the map according to the direction and distance Example 3 Describe and draw a simple road map. 2. Students have accumulated some perceptual experience in determining the position in their daily life. Through the first phase of study, they have been able to describe the relative position of objects in eight directions, such as up, down, left, right, front, back, east, south, west and north, and initially realized that the position of objects can be determined by two conditions in the plane. On this basis, this unit allows students to learn to determine the position of objects according to the two conditions of direction and distance, and draw a simple road map. Enable students to further understand things from the perspective of orientation, more comprehensively perceive and experience things around them, and develop the concept of space. 3. Let the students know the importance of determining the position according to the actual life. The textbook selects real-life materials to make students understand the role and value of what they have learned. For example, through the situation of "park orienteering", this paper introduces how to determine the position according to the direction and distance, so that students can understand the application of determining the position in life and experience the close relationship between mathematics and daily life. 4. Pay attention to creating activity situations and encourage students to explore independently and cooperate and communicate. Students already have the foundation of understanding things from the perspective of orientation, and with the growth of age, their language expression ability, hands-on operation ability and independent exploration ability have all improved. Therefore, in teaching, we should pay full attention to students' existing knowledge base and life experience, create a large number of activity situations, provide students with space for exploration, and let students further understand things from a directional perspective through observation, analysis, independent thinking, cooperation and communication. In this grade, students have a strong thirst for knowledge and curiosity. Teachers should fully mobilize students' enthusiasm and guide them to explore and think independently. And because of students' personality differences, different students have different ways of understanding things. Teachers should encourage students to express their views boldly and cooperate and communicate with their peers. Through this process, students learn to explore and think in different ways and constantly improve their thinking level.