读了《中小学数学》2010年第10期《对“近似数”的探讨》一文,很受启发,觉得对教材的研究非常必要,也是教师的必备基本功.但对文中的一些观点不敢苟同,想借贵刊一角提出来与该文作者和各位同行商榷.该文指出:“精确到哪一位与保留几个有效数字是两种不同的要求,是两个不同的过程,从表达效果上来讲,肯定有相吻合的时候,但也不尽相同.”并对不相同部分作出了如下解释:“例如:310.5(精确到十位),310.5≈310,十分位上的”0“省略了,但个位上的”0“就不能省,如果同时要求保留四个有效数字,310.5≈310.0,而只要求保留四个有效数字,310.5=310.5,这就没有四舍五入的必要.再如”513“这个数,精确到百 Read the ”primary and secondary mathematics“ 2010 the tenth period ”on the“ approximation ”“ a text, very inspired, that the study of textbooks is necessary, but also the basic skills of teachers, but some of the views Do not agree, would like to put your corner of the paper put forward to discuss with the author and colleagues .This article states: ”exact to which one and retain a few significant figures are two different requirements are two different processes , From the expression effect, there must be consistent, but also not the same. “And the different parts are made as follows:” For example: 310.5 (accurate to ten), 310.5 ≈ 310, ten bit 0 “is omitted, but ” 0 “on the first digit can not be saved. If at the same time, it is required to retain four valid digits, 310.5≈310.0, but only to retain four valid digits, 310.5 = 310.5, There is no need for rounding. Another example is ”513" this number, accurate to one hundred