Handphone...

My new NokiaE90.......

Your handphone number

1) key-in the first 3 digits of your handphone number (not the 01x number) into the calculator
2) multiply by 80
3) add 1
4) multiply by 250
5) plus last four digits of phone number
6) plus last four digits of phone number again
7) minus 250
8) Finally, divide by 2

Is this your handphone number????