《国家课程标准》在课程实施建议中指出:“估算在日常生活中有着十分广泛的应用,在教学中,教师要不失时机地培养学生的估算意识和初步的估算技能”。在倡导“数学核心素养”中学“有用的数学”这一大的教育环境下,估算越来越受到教师和学生的重视,但由于估算本身在解决问题策略上的多样性和计算结果的不确定性,估算教学也成为我们一线老师最为困惑 The National Curriculum Standard states in the course implementation suggestion: “Estimation has a very wide range of applications in daily life. In teaching, teachers should seize opportunities to develop students’ estimation and preliminary estimation skills.” In advocating “mathematics core literacy ” middle school “useful mathematics ” in this large educational environment, estimation is getting more and more attention by teachers and students, but due to the estimation itself, the strategy to solve the problem of diversity and computing The results of the uncertainty, estimation teaching has also become the most perplexing of our front-line teachers