四舍五入到“万”位或“亿”位求近似数是四年级上册《认识大数》单元的重要内容,以前所教版本与现在北师大版本在教学内容的尺度上把握完全不同。一直以来人教版与浙教版以及北师大版的这一内容安排都大致相同,但人教版与浙教版四舍五入求近似数“看尾数首位”问题都不是在学生自主探索中得出结论,而是由教材直接指出“看尾数首位”进行四舍五入,没有很好体现新教材遵循“学生自主探索”的教学理念,而最新版的北师大教材却 Rounding to the “million” bit or “million” bit for the approximation of the fourth grade is the “understanding of the number” unit of the important content of the previous version and the current version of the Beijing Normal University to grasp the full scale of the teaching content different. PEP has always been the same with the Zhejiang version and the Beijing Normal University version of this content arrangement are roughly the same, but the PEP and Zhejiao version rounded to find the approximate number of “see the first mantissa” are not in the students’ independent exploration Come to the conclusion, but by the teaching materials directly pointed out “see the first mantissa ” rounded, did not reflect the new textbook to follow the “student self-exploration ” teaching philosophy, and the latest version of the Beijing Normal University teaching materials