1. That is, read the question carefully and find out: what kind of question is this? What is the structure of the problem? What are the known conditions in the question? What are the problems or requirements in the problem, and so on.
2. analysis. That is to say, on the basis of examining the questions, make clear the connection or relationship between conditions and problems, analyze the ways to solve problems according to the requirements, explore the methods to solve problems, and realize the transformation from known to unknown. The basic idea of analysis is memory and speculation. For example, the definition, law, nature, law, formula of recall, solutions to typical problems related to association and matters needing attention. To determine how to solve the problem. Inference is a kind of speculation and attempt to solve problems.
3. Narrative. That is, after doing the above two tasks well, put the problem-solving into practice, that is, write the problem-solving process according to the problem-solving requirements. This step is what students often do.
Step 4 check. That is, check the problem-solving process. What if the inspection is wrong? Is there something wrong with the formula? Is the operation correct? Whether the format meets the requirements and so on.
Students, did you follow the above steps when solving the problem?
Why should the order of elementary arithmetic stipulate "multiply first, then divide, then add and subtract"?
There are two reasons for the stipulation of this operation order: first, there are more problems that need to be added and subtracted before multiplication and division in actual calculation than those that need to be added and subtracted before multiplication and division. This provision can greatly reduce the trouble of using brackets and make the operation simple. Second, from the development history of mathematics, addition and subtraction are the low-level forms of quantitative change, and multiplication and division are the high-level forms. Multiplication is a simple algorithm to increase the same number, and division is a simple algorithm to decrease the same number. Therefore, the ratio of multiplication and division is simple, fast and efficient, so the rule of using the ratio of multiplication and division as much as possible is produced.