It's really not hard to stump me since math was one of my worst subject.

Personally I would like to know who came up with this.

1. Grab a calculator

2. Key in the first three digits of your phone number (NOT YOUR 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?