A check-digit validation is used for all road vehicles sold in the United States and Canada. When trying to validate a VIN with a check digit, first either (a) remove the check digit for the purpose of calculation or (b) use a weight of zero (see below) to cancel it out. The original value of the check digit is then compared with the calculated ...

-Wikipedia. The check digit calculation is the computers own way of knowing if an item got scanned correctly. When a barcode is scanned, the group of digits are sent to the computer or register which instantly calculates the check digit based on the calculations found below. If the check digit does not match, the computer informs the teller to ...

The check digit is calculated thus: Multiply the first digit by 3; Multiply the second digit by the next prime number (5) Repeat this for each digit (missing 11 out on the list of prime numbers for the purposes of this algorithm) Add up all these products; …

An UPC Code consists of a unique 12-digit number and a barcode above it. In the most common application of a product UPC the first six numbers indicate the manufacturer. The next five digits are an item number, and the final number is the check digit. The check digit is added to help ensure that the UPC is valid.

チェックディジット（アメリカ英語: check digit 、検査数字）とは、符号の入力誤りなどを検出するために、元の符号に付加される数字のこと。 CD、C/Dと略される。