See if you can figure out this math equation!

1. Grab a calculator (you won't be able to do this one in your head);
2. Key in the first three digits of your phone number (NOT the area code);
3. Multiply by 80;
4. Add 1;
5. Multiply by 250;
6. Add the last 4 digits of your phone number;
7. Add the last 4 digits of your phone number again;
8. Subtract 250;
9. Divide number by 2.

Do you recognize the answer?