Got calculator? Posted on December 21, 2011 by GCD Enter the first three digits of your phone number (Not the area code). Multiply by 80. Add 1 Multiply by 250 Add the last four digits of your phone number. Add them again. Subtract 250 Divide by 2. Share this: Click to share on Facebook (Opens in new window) Facebook More Click to email a link to a friend (Opens in new window) Email Click to print (Opens in new window) Print Click to share on X (Opens in new window) X Click to share on Reddit (Opens in new window) Reddit Like this:Like Loading...