2.6 Check digits

Question 1

check digit

Answer 1

a calculation on data to create a number that is included with the data for error checking

Question 2

transcription errors

Answer 2

errors made when entering data

Question 3

calculating the modulus 11 check digit

Answer 3

• if a code is 8 digits, the first 7 are generated and the 8th is calculated
• each digit has a weighting, starting with 2 on the right
• multiply digit by the weighting
• add each subtotal
• divide by 11
• find the remainder
• subtract it from 11
• if the remainder is 10 then an X is used
• if there is no remainder a 0 is used

Question 4

steps to check code using modulus 11

Answer 4

if a modulus 11 check digit is used, the code will be divisible by 11 with no remainder

• give each digit a weighting, starting with 1 on the right
• multiply
• total
• divide by 11
• if there is no remainder it is a valid code

Question 5

Find the modulus check digit required for the code 3206736 and write the complete 8 digit code [4]

Answer 5

4

32067364

Question 6

A bank account number has a modulus 11 check digit. The account number 21336237 is entered.
Is this a valid number? [4]

Answer 6

99/11 = 9

yes