IS This YoUr NumBer?

1) key-in the first 3 digits of your handphone number (excluding number 9 )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) divide by 2 at last.
Is it your handphone number????