Proper application of variants in problem-solving teaching can help students cultivate divergent thinking.
The tactics of asking the sea are often "more wins than less" and "getting to the point". Students will be physically and mentally exhausted in the long-term training of the sea, and gradually step into a vicious circle of "low efficiency, heavy burden and low quality", thus gradually losing their interest and motivation in learning mathematics. Bivariate teaching just overcomes these shortcomings. With the help of variant questioning, displacement thinking and proposition transformation, we can guide students to learn induction and analogy, realize method induction and topic classification, effectively overcome the superficiality, blindness and narrowness of students' thinking, develop problem-solving ideas and cultivate inquiry consciousness, so as to achieve the effect of giving inferences by analogy.