title: mod 11 check digit with regex
body: <p>Is it possible to create a mod 11 check digit routine with a regex statement?</p>
  
  <p>THe nubmer is a 10 digit number,</p>
  
  <p>Step 1:
  A = (2nd number * 2) + (3rd number * 4) + (4th number * 8) + (5th number * 5) + (6th number * 10) + (7th number * 9) + (8th number * 7) + (9th number * 3))  </p>
  
  <p>Step 2:
  B = A / 11 (ignor remainder)</p>
  
  <p>Step 3:
  C = B * 11</p>
  
  <p>Step 4:
  D = A - C</p>
  
  <p>Step 5:
  11 - D must = the 10th digit</p>