《数学课程标准》指出:数学学习内容应当是现实的、有意义、富有挑战性的,这些内容要有利于学生主动地进行观察、实验、猜测、验证、推理与交流等数学活动。这就要求教师在教学中必须引导、鼓励学生进行猜想、验证。而鼓励学生猜想有着重要的意义——有利于激发学生的学习兴趣;有利于 The Mathematics Curriculum Standard states that the content of mathematics learning should be realistic, meaningful and challenging, which should be conducive to students’ initiative in mathematical activities such as observation, experiment, speculation, verification, reasoning and communication. This requires teachers in teaching must guide and encourage students to guess, verify. Encouraging students to guess has an important meaning - to help stimulate students’ interest in learning;