There are two basic tasks in learning discrete mathematics: first, by learning discrete mathematics, students can understand and master some mathematical concepts and basic principles that will be directly used in subsequent courses, master the scientific demonstration methods commonly used by computers, and lay a good mathematical foundation for subsequent courses; The second is to cultivate self-study ability, abstract thinking ability and logical reasoning ability in the learning process of discrete mathematics, so as to improve the professional theoretical level. Therefore, learning discrete mathematics is very important for the follow-up courses of computer, communication and other majors and for the future work of computer science. However, due to the discreteness of discrete mathematics, the dispersion of knowledge and the particularity of solving problems, some students are often confused about some problem-solving concepts and methods when they first come into contact with discrete mathematics, especially when doing proof questions, and feel that they have no way to start and can't find the correct problem-solving methods. Therefore, it is necessary to give proper guidance to the learning methods of discrete mathematics and analyze some problems encountered in the learning process. 1. Cognitive discrete mathematics Discrete mathematics is one of the core courses of basic theory of computer science, and it is also an important basic course for computer, application, communication and other majors. Its main goal is to study the structure and relationship of quantities, and the research objects are generally finite or countable elements, which fully embodies the discrete characteristics of computer science. The purpose of studying discrete mathematics is to make necessary knowledge preparation for the follow-up courses of computer, communication and other majors, further improve the ability of abstract thinking and logical reasoning, and provide necessary description tools and theoretical basis for the application of computers. 1. Definitions and theorems Multi-discrete mathematics is a logical reasoning discipline based on a large number of definitions and theorems, so understanding concepts is the core of learning this course. On the basis of learning these concepts, we should pay special attention to the relationships between concepts, and the entities that describe these relationships are a lot of theorems and properties. Part of the exam is to examine students' memory, understanding and application of definitions and theorems, so we should really understand the true meaning of each basic concept given in discrete mathematics. For example, the definition of proposition, five basic conjunctions, principal disjunctive paradigm and principal conjunctive normal form of formula, three inference rules and reduction to absurdity; Definition of five operations of set; The definition of relationship and its four properties; Definition of function (mapping) and several special functions (mapping); Definition of graph, complete graph, simple graph, subgraph and complement graph; The definitions of simple path and basic path in graphs and the isomorphism of two graphs: the definition of tree and minimum spanning tree. Mastering and understanding these concepts is very important for learning discrete mathematics well. 2. Strong methodology In the learning process of discrete mathematics, we must attach importance to and master the problem-solving methods of discrete mathematics. It is extremely important to find suitable ideas and methods to solve problems when doing problems. If you know how to do or prove a problem, you can do or prove it easily. It will get twice the result with half the effort. In discrete mathematics, although there are many kinds of problems, the solution of each kind of problems has rules to follow. Therefore, we should be good at summarizing and summarizing the regular contents in lectures and peacetime review. In the usual lectures and review, the teacher will summarize various ideas and methods to solve problems. As students, we should first be familiar with and know how to use these methods, and at the same time, we should be diligent in thinking and explore several solutions to a problem as much as possible. 3. Discrete mathematics with strong abstraction is characterized by the concentration of knowledge points, which requires higher abstract thinking ability. Because of the abstractness of these definitions, beginners often cannot directly establish their connection with objective things in the real world in their minds. No matter which discrete mathematics textbook it is, each chapter will list several definitions and theorems first, and then the direct application of these definitions and theorems. Without good abstract thinking ability, it is really difficult to learn discrete mathematics. Therefore, in the study of discrete mathematics, we should pay attention to the cultivation and training of abstract thinking ability and logical reasoning ability, which is extremely important for all kinds of work in the future. These difficulties in learning discrete mathematics can be gradually solved by learning more, watching more, carefully analyzing the problem-solving process of typical examples given in lectures and practicing more. It is emphasized here that a deep understanding and mastery of the basic concepts, theorems and conclusions of discrete mathematics is one of the important prerequisites for learning discrete mathematics well. Therefore, students should remember and understand all these basic definitions and theorems accurately, comprehensively and completely. 4. Although the three internally related discrete mathematical systems come from different disciplines, they are connected to form an organic whole. Through careful analysis, we can find out the internal relationship and regularity of knowledge among the three parts. For example, set theory, function, relation and graph theory all have the same or similar ideas and proof methods. Second, cognitive problem-solving norms Generally speaking, the examination requirements of discrete mathematics are divided into: understanding, understanding and mastering. Understanding can correctly distinguish related concepts and methods; Understanding is the ability to correctly express the meaning of related concepts and methods; Mastery is flexible application on the basis of understanding. In order to assess students' understanding and mastery of these three parts, the types of test questions can generally be divided into: true or false questions, fill-in-the-blank questions, multiple-choice questions, calculation questions and proof questions. True or false questions, fill-in-the-blank questions and multiple-choice questions mainly involve basic concepts, basic theories, important properties and conclusions, formulas and their simple calculations; Calculation questions mainly assess students' basic application skills and speed, and require writing a complete calculation process and steps; Proof questions mainly examine the ability of logical reasoning by using concepts, properties, theorems and important conclusions, which requires a strict reasoning and demonstration process. The biggest difficulty in learning discrete mathematics is its abstraction and rigor of logical reasoning. In discrete mathematics, if you want to solve a problem or prove a proposition, you must first understand the meaning of the problem, and then look for ideas and methods to solve the problem or prove it. When you believe that you have found ideas and methods to solve or prove problems, you must write them out strictly. A well-written problem-solving process or proof is a series of statements, each of which is obtained by simple reasoning from the previous statements. It is very important to write the problem-solving process or proof carefully, which can not only make readers understand, but also ensure the accuracy of the problem-solving process or proof. A good problem-solving process or proof should be clear, convincing and concise. In response to this requirement, teachers will provide a large number of typical examples for students to refer to and learn during lectures. Through the study and training of discrete mathematics, students can learn the general laws and methods of dealing with problems in discrete mathematics. Once they master discrete mathematics, a thinking method to deal with problems, it is no longer difficult to learn and master the knowledge of discrete mathematics.