According to the problem setting and related knowledge, the eight skills exclusion method for solving multiple-choice questions excludes obviously incorrect options, so the only remaining option is naturally the correct option. If you can't get the right options right away, you can at least narrow the range of choices and improve the accuracy of solving problems. Exclusion is an indirect method to solve multiple-choice questions, and it is also a common method to solve multiple-choice questions. Number-shape combination method: To solve multiple-choice questions related to figures or images, the thinking method of combining mathematics is often used, and sometimes other methods are used comprehensively. Special case test method: adopt special cases (special value, special point, special figure, special position, etc.). ) and verify them to get the correct options. Because this proposition holds true for general situations, it also holds true for special situations. Substitution method: substitute the selected branch into the stem of the question or substitute the question into the selected branch for inspection, and then make a judgment. Observation: Observe the characteristics of the trunk and the selected branches, and make a choice by distinguishing the differences and relationships of the selected branches. Enumeration: enumerate all possible situations and then make a correct judgment. For example, if you change a RMB with a face value of 10 into small change, the RMB with a face value of 10 in 2 yuan will be enough. There are () (A)5 kinds (B)6 kinds (C)8 kinds (d) 65,438+00 kinds of changes. Analysis: If you set the face value of RMB X as 2 yuan and the face value of RMB Y as 1 yuan, it is not difficult to list the equations. This equation has six pairs of non-negative integer solutions, so choose B. undetermined coefficient method: to require a certain functional relationship, you can first assume the undetermined coefficient, then list the equation (group) according to the meaning of the question, and then get the undetermined coefficient by solving the equation (group), thus determining the functional relationship. This method is called undetermined coefficient. Incomplete induction: When a mathematical problem involves many or even infinite situations and it is difficult to start from chaos, the effective method is to find out the general law and solve the problem by investigating some simple situations. This method has some limitations and can't be used as a strict demonstration method, but it can help us find and explore the laws of general problems and find solutions to them. The direct solution of three problem-solving strategies for fill-in-the-blank questions directly starts from conditions, and obtains the correct answer through calculation and proof according to formulas, rules, axioms and theorems. Of course, in the process of solving, we can skip some unnecessary steps and try to find the answer to the question through mental arithmetic, which is suitable for solving some basic problems. This method requires students to memorize basic concepts, formulas, rules, properties, theorems and axioms. , and deeply understand and apply them. For example, in order to ensure information security, information needs to be encrypted and transmitted. The sender corresponds to the ciphertext from the plaintext (encryption), and the receiver corresponds to the plaintext from the ciphertext (decryption). The known encryption rule is that plaintext X, Y, Z corresponds to ciphertext 2x+3y, 3x+4y, 3z. For example, plaintext 1, 2,3 corresponds to cipher text 8, 16544. 17,27, Decrypting plaintext is parsing: If we analyze this problem carefully, we can know that it is a problem of ternary linear equations. From the meaning of the question, we can set these three plaintext numbers as x, y and z, and get 2x+3y =12x = 33x+4y =17, and get y = 23z = 27. A method of calculation and reasoning by using special numerical values or making special graphs. When solving problems with special value method, we should pay attention to selecting values that meet the conditions and are easy to calculate. This kind of question usually has the nature of * * *: some general conditions are given in the stem of the question, and some specific conclusions or numerical values are required. The conditions provided by the problem can be specialized in solving. Make it a general special figure or question, and the answers to these special figures or questions are often the answers to the original questions. Using special value method to solve problems, we can not only select special values to substitute into the original problem, so that the original problem can be solved, but also make special graphs that meet the conditions for calculation or reasoning. In recent years, there have been many problems in exploring the types of laws in the senior high school entrance examination questions. The main way to solve this kind of problem is to adopt incomplete induction, and solve the problem through experiment, guess, trial and error verification and summary. The classification idea of solving geometric multi-problems with classification idea refers to a mathematical thinking method of dividing the research objects into different categories and dealing with them separately according to the essential attributes of mathematical concepts. Correctly applying the idea of classification is an important method to solve some mathematical problems. The idea of classified discussion is the condition for thinking about mathematical problems. When the conclusion is not clear, or when the meaning of the problem contains uncertain parameters or figures, the complex problem is decomposed into several simple problems to solve. When using classified discussion ideas to solve problems, we should pay attention to: 1. Carefully examine the questions, carefully analyze them, and don't rush to write, paying attention to one thing and losing another; 2. For the problems that need to be classified and discussed, it is necessary to clarify the classification objects and standards; 3. There is no duplication or omission between categories; 4. Finally, various results are summarized. In addition to strengthening the skills and methods training of fill-in-the-blank and multiple-choice questions, we should also summarize the ideas and methods of solving problems in the usual review. For example, in geometry problems, congruence method and similarity method should be two basic methods. In order to master these two methods better, you should be familiar with a pair of congruences or a pair of basic figures of similar triangles. The following figure shows the basic graphics of congruent triangles. It is a trick to accumulate a large number of basic graphics and learn geometric graphics on this basis. Every important concept and theorem has a basic figure, and a three-line octagon can be regarded as a basic figure. The side length, inner angle, trigonometric function, midline, height, bisector and area of a right triangle with a special angle also constitute a basic figure.