Do you want the calculator to know your number???
Only works for the seven-digit numbers. In case of mobile phones, just use the last 7 digits.
Check your phone number e.g. 0-918-123-4567
1) Key-in the first 3 digit of your phone number into a calculator
2) multiply by 80
3) add 1
4) multiply by 250
5) plus last four digit of phone number
6) plus last four digit of phone number again
7) minus 250
8) divide by 2 at last
Is it your phone number???