一、引言长期以来，中学数学教学十分强调推理的严谨性，遵循三段论式的演绎推理．但事实上，很多事物对象是不便或不能用演绎的方法去推理的．从数学发展史看，在数学的每一个重大发明创造过程中，除演绎推理外，还要进行大量的合情推理．因此，在中学阶段，忽视合情推理而过 I. INTRODUCTION For a long time, mathematics teaching in middle schools has emphasized the rigor of reasoning and followed the deductive reasoning of the three-segment theory. But in fact, many objects are inconvenient or cannot be deduced by deductive methods. From the perspective of the history of mathematics development, in addition to deductive reasoning, in the process of each major invention of mathematics, a large amount of reasonable reasoning is required. Therefore, in the middle school stage, ignore the reasonable reasoning