9464

Check Digit Schemes

Identification numbers often have a check digit appended to them in order to help catch copy and transmission errors. Seven common check digit schemes are illustrated here. The "new example" button gives a random identification number of the desired type. Use the popup menu to select the check digit, then check your answer. If your answer is incorrect, you can view the appropriate computation and try again. The "fixed example" and "illustrate error" options show several of the most common errors and allow you to explore whether a given check digit scheme will catch such errors.
The United States Postal Service money order check digit scheme requires that the check digit (the 11th digit) be the remainder upon division by 9 of the sum of the first 10 digits of the identification number.
The traveler's check scheme requires that the check digit be chosen so that the sum of all 10 digits (including the check digit) is divisible by 9.
In the airline ticket scheme, the check digit (the 12th digit), is the remainder upon division by 7 of the 11-digit identification number.
Given a UPC number , the check digit is chosen so that the weighted sum is divisible by 10.
Given a bank routing number , the check digit is the remainder upon division by 10 of the weighted sum .
For a 10-digit ISBN number with the first nine digits , the check digit is chosen so that the weighted sum has a remainder of 0 upon division by 11. The symbol X is used if the check digit must equal 10.
The credit card check digit is computed so that is divisible by 10. The number is the number of digits in the odd-numbered positions whose value exceeds 4.
  • Contributed by: Marc Brodie
  • (Wheeling Jesuit University)

SNAPSHOTS

  • [Snapshot]
  • [Snapshot]
  • [Snapshot]
  • [Snapshot]
  • [Snapshot]

DETAILS

Reference
[1] COMAP, For All Practical Purposes, New York: W. H. Freeman and Company, 2009.
    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.









 
RELATED RESOURCES
Mathematica »
The #1 tool for creating Demonstrations
and anything technical.
Wolfram|Alpha »
Explore anything with the first
computational knowledge engine.
MathWorld »
The web's most extensive
mathematics resource.
Course Assistant Apps »
An app for every course—
right in the palm of your hand.
Wolfram Blog »
Read our views on math,
science, and technology.
Computable Document Format »
The format that makes Demonstrations
(and any information) easy to share and interact with.
STEM Initiative »
Programs & resources for
educators, schools & students.
Computerbasedmath.org »
Join the initiative for modernizing
math education.
Powered by Wolfram Mathematica © 2014 Wolfram Demonstrations Project & Contributors  |  Terms of Use  |  Privacy Policy  |  RSS Give us your feedback
Note: To run this Demonstration you need Mathematica 7+ or the free Mathematica Player 7EX
Download or upgrade to Mathematica Player 7EX
I already have Mathematica Player or Mathematica 7+