In junior high school, the solution must be written, and the teacher may not write it during the lecture, but there are certain requirements during the senior high school entrance examination. Some marking teachers even deduct one point, which was emphasized by my junior high school teacher.

As for the answer, sometimes it is used, sometimes it is not used, but the result should be clearly pointed out at the end of the question, but sometimes it is not used.

But in the form of "so ...", "so ..." and "summary ..." (generally a topic to be discussed in different situations)

The steps of reading more examples in the book are standardized and complete.