1, define the goal: first, what is the goal of the problem. Determine what problems need to be solved and understand the background and related information of the problems.

2. Reverse thinking: The core of reverse thinking is reverse thinking. Starting from the goal and result of the problem, imagine that you are from the front to the back, but the actual problem-solving process is reversed.

3. Decompose the problem: decompose the problem into several small steps or parts, and each step is to approach the final target result.

4. Establish a mathematical model: according to the characteristics and known conditions of the problem, establish a suitable mathematical model. You can use charts, equations, inequalities, etc. Express the relationship between various quantities.

5. Step-by-step derivation: Starting from the last step, gradually deduce until the goal of the problem is achieved. At every step, we must ensure that all conditions and relationships are properly handled and transformed.

6. Integrate the answers: Finally, make sure the logic is clear and coherent when integrating the answers. Although backward deduction is an effective problem-solving skill, not all problems are suitable for use. For some specific problems, the backward method can simplify the problem and improve the efficiency of solving. When solving complex problems, it is very important to use different problem-solving skills and methods flexibly.

The application of mathematical inverse deduction;

1. algebraic problem: when solving algebraic problems, backward deduction can help us think backwards and find clues to solve the problem. For example, when solving multivariate equations or complex equations, you can start with the last equation or unknown number and deduce it step by step until you find all the unknown numbers.

2. Geometric problems: In geometric problems, backward deduction can help us think backwards and find solutions to the problems. For example, when solving a geometric proof problem or finding the congruence relationship of geometric figures, we can start from the conclusion and deduce it step by step until we find a sufficient condition that can be proved.

3. permutation and combination problem: when solving permutation and combination problem, reverse reasoning can help us think backwards and find the strategy to solve the problem. For example, when solving the problem of arrangement or combination, we can think backwards from the target result and find out all possible arrangements or combinations.

4. Mathematical reasoning problem: When solving mathematical reasoning problems, reverse reasoning can help us think backwards and find clues to solve problems. For example, when solving the problem of series or mathematical induction, we can start with the last number or condition and deduce it step by step until we find all possible series or conditional relations.