The problem of precision loss when calculating guide line position

[bigfacewo]

After setting Scala to two decimal places, and then restoring it back, the location of guide line has changed. For example, add a line whose position is 700, and then set scale as 0.66, 0.67, 0.68, 0.69, and 1. Then it is found that the original position of the line at 700 is 698. How can I solve this problem?