Works only for 7 digit numbers
1) Write down the first 3 digits of your phone number? (do NOT include the area code)
2) Multiply by 80
3) Add 1
4) Multiply by 250
5) Add in the last 4 digits of phone number
6) Add in the last 4 digits of phone number again
7) Subtract 250
8) Divide by 2
Is the result your phone number?
