"The number is not there, but it serves the purpose".. I can agree with that.
In geometry there are these rules:
point - point = vector
point + vector = point
vector + vector = vector
You are not allowed to add points, unless you scale them with scalars that add up to 1:
0.7*point1 + 2*point2 - 1.7*point3 = point
above calculation is ok because 0.7 + 2 - 1.7 = 1
Can you see why the sum of scalars needs to be 1?
I did not answer your question, but I wanted to give you some more to think about. With points, the important thing is the distance between two points and other relations.. the actual position is not important (it can always be fixed arbitrarily).