对近似数的精确度及其有效数字的确定问题是同学们学习中的一大难点.因为此处内容与其它章节联系不强,平时也很零星的用到,因此为了学好此处内容,特提出以下几点注意:一、有效数字的确定对于一个近似数,从左边第一个非零数字起到末位数字止,所有数字都 The accuracy of the approximate number and the determination of its effective number of figures is one of the most difficult points in the study for the students because the contents of this section are not strong links with other chapters and are often used sporadically. Therefore, in order to learn the content here, Put forward the following points: First, the determination of significant figures For an approximation, from the first non-zero figure on the left until the last figure, all figures are