Math diary refers to a mathematical short story created by students in combination with their own mathematical knowledge and life practice. Applying mathematics knowledge to solve difficulties in life can train students' thinking ability, improve students' interest in mathematics and stimulate students' good habits of carefully observing life.

Math diary improved his learning ability in mathematics through interesting forms. For example, if he encounters a problem in class, he can speak it out in math diary by studying hard.

Excerpt the stem of the question into math diary, and then write down the thinking, methods, means and skills of solving the problem in detail, including the problem of giving inferences by analogy, which has played a role in consolidating and reviewing knowledge.