Chapter 0

Exercise 5. This software calculates the ISBN check digit. Use it to verify that 0395872456 is valid. Now enter the same number with one digit incorrect. Was the error detected? Enter the number with two digits transposed. Was the error detected?

Exercise 6. This software determines the two check digits for the mod 11 decimal error correction scheme discussed in this chapter. Run the program with the input 21355432, 20965744, 10033456. Then enter these numbers with the two check digits appended with one digit incorrect. (Please type in 'x' instead of '10' for the check digits.)

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