“四舍五入”是在科学研究中常常遇到的对有效数值的取舍问题。在选定有效数字位数之后遇4则舍,遇6则进,这已是人所共知的事,在此不再赘述,但遇5是舍,还是进,目前尚不统一。我们查阅了多种国内著名的学术期刊的稿约,他们提出在5前遇奇数则进,遇偶数(包括零)则舍的原则来处理有? “Rounding” is a trade-off between valid numbers often encountered in scientific research. In the selected effective number of digits after the case of 4 homes, the case of 6 into, this is a well-known thing, not repeat them here, but the case of 5 homes, or into, is not uniform. We have reviewed the drafts of a number of well-known academic journals in China. They proposed that the principle of dealing with odd numbers before entering an even number (including zero)