title: How to convert UPC-A to UPC-E?
body: <p>We would like to convert the 12 digit UPC-A to 8 digit UPC-E. Can you tell me which is the best way to do this without having to use my own code to convert?</p>
  
  <p>I got many formula for convert the 8 digit UCC-E to 12 digit UPC-A but not reverse.</p>