Let's talk about calculation first. Computing ability is really one of the important factors that affect the ups and downs of grades, and computing errors are only the superficial phenomenon of computing ability. Therefore, to solve the so-called calculation error, we must dig deep into the superficial roots. To put it simply, the calculation is mainly based on the following points: 1, and the draft is too messy. Many students are confused by a certain step in the calculation, which leads to low-level mistakes such as missing negative numbers and missing 3, and they become more and more confused in the later calculation. 2, the basic calculation is not enough. Like general factorial solutions, complex fractional simplification, fractional reduction, etc. Because the basic work is not solid and there are mistakes. 3. The four-dimensional potentiometer is wrong. This kind of problem is also a common mistake made by students in different schools. There are two reasons for this. First, there are many such questions at ordinary times, and they will always follow certain habitual calculation formulas and will not change. Second, there are too many complicated calculations for a question in front, which requires some efforts, and it will be very tiring to ask questions later. This is what Beijing Xindong Youneng told me.