估算对培养学生计算或测量结果的概括性、整体性,对数量关系和空间形式进行合理的判断和推理,提高学生处理和解决实际问题的能力有着非常重要的意义。一是根据教材内容设计切合实际的教学方法;二是训练和培养学生估算的能力;三是指导学生对估算的运用。 It is of great importance to estimate students ’reasonable ability to handle and solve practical problems by reasonably estimating and reasoning the generalization, integrity, quantitative relationship and spatial form of the students’ calculation or measurement results. First, according to the content of the textbook design practical teaching methods; Second, training and training students ability to assess; Third, guide students to estimate the use of.