One object can be considered from different angles:
How long is the table? — “Four feet,” an instance of quantity.
What is the table like? — “Black” or “smooth,” instances of quality.
Similarly, three glasses of water concern number, while the warmth of water concerns sensible quality.
The word “more” does not always indicate quantity as a category. “Warmer” compares degrees of a quality; we must identify the actual attribute under discussion.