Puzzle Corner

Here is a math trick that will stump you ...
1.  Grab a calculator

2.  Key in the first three digits of your phone number (no 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 you phone number again

8.  Subtract 250

9.  Divide number by 2

Do you recognize the number? 
It should be your telephone number.