Intensive Property-Concentration

How is concentration an intensive property? I mean if you add more amount of a substance(mass), the number of moles increase and so the concentration increases. So why is concentration not an extensive property and is an intensive property?

 

Ok, suppose we have a 2M solution of sulphuric acid and then we add some more suplhuric acid to it. As concentration is an intensive property, the concentration of sulphuric acid even after adding suplhuric acid should remain same but it is not like this. Or does it still remain the same? Because, I think that when we add more sulphuric acid though we are increasing the number of moles of sulphruic acid but we are also increasing the volume of the solution (as the new coming suplhuric acid makes the volume increase). So does that make the concentration remain the same?
The definition of an Intensive property is: Properties which do not depend upon the quantity of mater present are called intensive properties. So concentration should not depend upon the quantity of sulphuric acid (matter) present. So whether we add 4 gram or 4kg the concentration shouldn't change. But is it so? I don't think so. So that's why I am confused.

 

So "Independent of amount of matter" , here matter means the whole solution of suplphuric acid and water and not pure sulphuric acid..right?