1 How to kill multiple-choice math questions
1. direct solution
Direct solution is a method that directly starts from the conditions of the topic, uses known axioms, theorems, definitions, formulas and rules, and draws the correct conclusion of the topic through a series of logical reasoning, and then compares it with the selected branches to select the serial number of the correct answer. It is the main method to solve multiple-choice questions, and its essence is to equate multiple-choice questions with solving problems.
2. Verification method
The so-called "verification method" is a multiple-choice solution that substitutes the conclusions provided by the selected branches into the stem of the question for operation or reasoning, and judges whether it meets the conditions of the question, so as to eliminate the wrong selected branches and get the correct answer.
3. Number-shape combination method
The combination of numbers and shapes means that when dealing with mathematical problems, abstract mathematical language can be accurately combined with intuitive geometric figures for thinking, and abstract thinking and image thinking can be combined through "helping numbers with shapes" and "helping shapes with numbers" to realize the transformation from abstract to intuitive and from intuitive to accurate, so as to achieve a simple method to solve problems. The combination of numbers and shapes is of great significance in solving mathematical problems.
4. Special case method
The so-called "special case method" is a method that uses some special situations (including special values, special points, special figures, special positions, etc.). ) that is, to meet the problem to replace the general conditions and draw special conclusions, so as to test and screen each selected branch and get the correct choice. It is worth noting that when using the special case method, if two or three branches meet the conclusion, we should choose the special case test or use other methods to solve it. Of course, this also shows that proper selection of special cases is helpful to improve the accuracy and simplicity of solving problems.
2 math multiple-choice problem-solving skills
1. Special value test method
For a general mathematical problem, we can specialize the problem in the process of solving it, and use the principle that the problem does not hold in special circumstances and does not hold in general circumstances to achieve the purpose of removing the false and retaining the true.
2. The principle of extremism
Analyze the problem to be studied to the extreme state, so that the causal relationship becomes more obvious, thus achieving the purpose of solving the problem quickly. Extreme value is mainly used to find extreme value, range and analytic geometry. Many problems with complicated calculation steps and large amount of calculation can be solved instantly once extreme value analysis is adopted.
3. Exclusion method
Using the information provided by the known conditions, three wrong answers are eliminated from the four options, so as to achieve the purpose of correct selection. This is a common method, especially when the answer is a fixed value or has a numerical range, special points can be used instead of verification to exclude it.
4. Valuation selection method
Some problems cannot (or are not necessary) be accurately calculated and judged due to the limitation of subject conditions. At this time, we can only get the correct judgment method from the surface by means of estimation, observation, analysis, comparison and calculation.