Bank card numbers are not random, they carry information for the card processor (Visa/Mastercard etc), bank which issued the card, the account and checksum. More on the subject is available at http://en.wikipedia.org/wiki/Bank_card_number
Make code which enters card number and validate it i.e. writes VALID or INVALID number has been entered.
You can code the solution in any programming language during the weekend and have to submit it to email@example.com latest on Sunday February 16th.
On Monday we will upload the solutions on GitHub https://github.com/OLIMEX/WPC
You can play with your real name or with nick if you want to be anonymous, we will not disclosure your personal info if you do not want to.