This disk converts Roman numerals into Arab numerals and vis versa.
Learning Roman numerals is a good way to exercise logic and counting.
Even if Roman numerals are no more in use today, they can still be found in our daily lives, on monuments, watch dials, to number book chapters, to date films, etc. It is quite common to find inscriptions with Roman numerals on the many Roman remains that can be visited in Europe.
To get interested in Roman numerals is also useful as it links us back to the Antique world which influenced greatly our modern societies.