Among 0,1,2,3,4,5,6,7,8,9 only 'zero' has the value which is ever changing; if we belief that the theory of Big Bang is right and our Universe is expanding. We can easily compare one with another one, two with another two and so on but we can not able to compare zero of a 'thing' with another zero.
But if we define zero then we can easily compare zero of a thing with another zero of the same thing.
In case of our expanding universe we can define zero as the inverse of the diameter of the universe or zero is inversely proportional to the radius of the universe.
In case of open space, in which our universe is expanding, zero is undefined because we don't know the radius of open space. In case of our universe, zero has value, which is very less and decreasing with expansion of it.
So when we multiply a distance measured in light year or in parsec with zero (zero of our universe) it has some value which is less than one.
But if we define zero then we can easily compare zero of a thing with another zero of the same thing.
In case of our expanding universe we can define zero as the inverse of the diameter of the universe or zero is inversely proportional to the radius of the universe.
In case of open space, in which our universe is expanding, zero is undefined because we don't know the radius of open space. In case of our universe, zero has value, which is very less and decreasing with expansion of it.
So when we multiply a distance measured in light year or in parsec with zero (zero of our universe) it has some value which is less than one.