>>12546034A number is just a description. They are used to assess situations.
There is one mammoth. There are three trees. There are five apples.
These are things that early man would have been concerned with, as humans are social hunter gatherers. If there is one mammoth, maybe we can just charge into it. If there are twenty mammoths, maybe we should just pick one off when we can. The number is a concept used to make such qualitative judgments.
The concept also exists across animals. Try getting an adult dog excited for food only to give them three or four pieces of kibble. They're probably doing to have an emotional response, maybe they'll get angry or they'll just look at you or beg until you give them more. There's a quantitative assessment going on, and the concept of the number is just a discretization of this assessment.