Question:Why Round Number have to be used here?

I came across with this annoying problem there days.It seems that one Round Number component have to be used ,or the result would be wrong or right randomly. What is wrong here and how to avoid it? See attached pictures and file.thanks.

Round (20.6 KB)

could you please state your final objective?

if you want to filter out items for which distance is zero, you can use Smaller Than component with a very small value, like:

Round (16.6 KB)

Yes,that is what I want. Thanks.
Using one “smaller than” component is better than round it.I will give a try.