0 used to mean an amount or number of something without saying exactly how much or how many -- いくらか, いくつか
1 used to mean a part of a larger amount or number of something and not all of it -- 一部(の人、物)
Some of the children were frightened.
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
道路がどれだけ長くても、一歩一歩完了することができますし、足跡をマークしなければ、道路がどんなに短くても完了することはできません。