A good answer might be:

Representations

What you wrote is a representation of the number. Here is one representation:

XII

This may not be the representation you used for your number. Here is another representation for that same number:

///// ///// //

Perhaps you used this representation:

12

or this:

twelve

or this:

11002

QUESTION 3:

Are XII, ///// ///// //, and 12 different numbers?