Question

This is a digit in a sequence which is arithmetically calculated from the other digits in the sequence. It is used to verify that the sequence is correct.

a) Sequential digit
b) Check digit
c) Calculated digit
d) Verification digit

Answer 1

A 'check digit' is a digit added to a sequence of numbers to verify their accuracy and integrity, calculated based on the other digits' values. It helps in detecting errors in number sequences like credit card numbers or ISBNs.

Step-by-step explanation:

This is a digit added to a sequence of other digits, usually at the end, that is calculated based on the value of the other digits. Its primary purpose is to verify the accuracy and integrity of the sequence of numbers, such as a credit card number, ISBN for books, or a UPC. For example, in the ISBN-10 system, the check digit is calculated by multiplying each digit by its position number (from 2 to 10), summing these products, and then finding the remainder when this sum is divided by 11. A remainder of 10 is represented by an 'X'. This helps to detect if a number has been entered or written down incorrectly if the calculated check digit does not match the check digit of the provided sequence.