Let me tell you what time it is. First, some people can't change it if they change it. They have a direction in doing math problems. Sometimes they do change in the same formula, but every math problem gives you a direction of change. If you don't master the direction of change, you will certainly never get out. In fact, no matter how powerful a math expert is, he will often run into a wall and sometimes he can't walk. Therefore, a true master of mathematics should not only have knowledge, but also have perseverance.

Second, in fact, everyone will make mistakes in calculation, even the most powerful experts will keep checking and making changes when they do math problems. Even so, they just avoid making fewer mistakes.

Learning mathematics is important to understand concepts and formulas, and advanced is to learn some mathematical methods, not only in mathematics, but also in various fields of knowledge. Such as induction, recursion, recursion (that is, reverse reasoning). The highest level of learning mathematics is to learn how to analyze and solve problems.