5.
Subtract the remainder from the modulus.
The result becomes the check digit. In this case, the check digit is 2.
10 - 8 = 2
S u m o f D i g i t s C a l c u l a t i o n
This is an example of how the printer uses Sum of Digits to calculate a
check digit for this data:
5 2 3 2 4 5 2 1 9
1.
Weights are applied to each digit, starting with the last digit in the
weight string. They are applied right to left, beginning at the right-most
position of the field. Remember, a weight string must contain at least
two different numbers. This example has a weight string of 1,2,3,4:
field:
weight string:
2.
Each digit in the field is multiplied by the weight assigned to it:
field:
weight string:
products:
3.
Next, the digits of the products are added together. Two-digit products
are treated as two separate digits.
This is the sum of the digits.
2 + 0 + 2 + 6 + 6 + 1 + 6 + 5 + 4 + 3 + 3 + 6 = 44
4.
Divide the sum of the digits by the modulus (10 in this case), only to the
whole number. The balance is called the remainder.
5 2 3 2 4 5 2 1 9
4 1 2 3 4 1 2 3 4
5 2 3 2 4 5 2 1 9
4 1 2 3 4 1 2 3 4
20 2 6 6 16 5 4 3 36
4
10 44
40
4
Defining Field Options 3-15