Chapter 18, Problem 40E

Explanation of Solution

Detection of errors using the check digit:

The individual digits in the number are added together and the unit digit of the result is called as check digit.

• It is used for error detection.
• The check digit is stored with the number.

For example,

• Consider the number: 6668-6, here 6668 is the required number and 6 is the check digit.
• If the number is received as 1668-6 instead of 6668-6 incorrectly. This can be identified by using the check digit as follows:
• Step 1: Count the given number from left to right...