一行一个数据，输入数据后自动更新显示相加的结果，比较方便计算，相当于excel的“sum”函数，偶尔需要计算一些数据没必要用上offic这么庞大的软件，就可以用上-A row of data, automatically updated results show that the sum of the input data, more convenient, equivalent to excel in the " sum" function, occasionally nee