论文部分内容阅读
江西永新县芦溪中学刘琴同学问：“怎样记录测量结果？3．7cm和 3．70cm有区别吗？”对这个问题的回答是肯定的,即它们是有区别的．我们知道,测量长度必须要使用测量工具,例如大家通常使用的直尺,它的分度值是 1mm．用这种直尺测量一个物体的长度AB时,常将直尺的“O”刻度线对准它的端点A,再看端点B落在直尺的哪个刻度上(如图所示)．如果B恰好落在刻度线3和刻度线4之间的第7个小空格范围内,同学甲可能将长度AB读作3．70cm(他认为端点B恰好落在小刻度线上),而同学乙可
Liu Qin, Luxi Middle School, Yongxin County, Jiangxi Province, asked: “How to record the measurement results? Is there a difference between 3.7cm and 3.70cm?” The answer to this question is yes, that is, they are different. We know that to measure the length we must use a measurement tool, such as the ruler usually used by everyone, and its index value is 1mm. When using this ruler to measure the length AB of an object, always align the “O” scale of the ruler with its endpoint A, and then see which scale of the endpoint B falls on the ruler (as shown). If B happens to fall within the 7th small space between tick 3 and tick 4, classmate A may read length AB as 3.70cm (he thinks that end B happens to be on the small tick mark). B can