Mathematics
With mathematics, you can calculate things which we intuitively cannot imagine.
Explanation
Numbers are not apparent in nature as physical entities. They are no points either. Anyway, you can work with them in mathematics. You should be aware that every visualisation can lead to absurd situations.
You can write the number 1 as 0.999... and then you don't know if this is the same point. If you delete the point 1 on the number line, will the point 0.999... then remain or does it disappear aswell?