《小学数学新课程标准》指出:“数学是人们生活、劳动和学习必不可少的工具。”因此,新标准对数学课程的内容也作了较大的调整,其中就增加了“能选择合适的估算方法”这一部分的内容。“估算在日常生活与数学学习中有着十分广泛的应用。培养学生的估算意识,发展学生的估算能力,让学生拥有良好的数感,具有重要的价值。”传统教材中,估算主要运用于对运算的结果进行粗略的检验,使得不少教师片面地把估算理解成一种机械 The New Curriculum Standard for Elementary Mathematics states: “Mathematics is an indispensable tool for people’s life, work and study.” Therefore, the new standard also made a big adjustment to the content of mathematics curriculum with the addition of “ Can choose the appropriate estimation method ”the content of this part. “Estimation has a very wide range of applications in daily life and mathematics learning.It is of great value to cultivate students ’estimation awareness, develop students’ estimation ability and make students have a good sense of number.” In traditional textbooks, the estimation is mainly used On the result of the operation of a rough test, so that many teachers one-sided estimate of understanding as a mechanical