magika

enter the first three digits of your mobile number (omit 012, 016, 019 etc.) to the calculator

* multiply with 80

* add 1

* multiply with 250

* add the last four digits of your mobile number

* again, add the last four digits of your mobile number

* minus 250

* divide by 2

ta-daa! the number shown on your calculator is your mobile number ;)