Something of interest to you. Try this out !!!
Really amazing !

1) key-in the first 3 digits of your handphone number (ex. +673 8877766, the 3 digits is 887) 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