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Modulo11 CheckDigit Calculation

The field entered is 9434578423. The last digit (3) is the check‑digit. The actual data value is 943457842.

The following occurs:

1. CA Ideal assigns Modulo‑11 weights. Modulo‑11 weights are the consecutive digits 2 through 7. They are assigned beginning on the right side of the data value.
2. After weight 7, the series begins again with 2 until each digit of the data value is assigned a weight, as shown below:

1. CA Ideal assigns each digit in the data value a Modulo‑11 weight.
2. CA Ideal multiplies each digit by its assigned weight.
3. CA Ideal adds the products together (36 12 6 28 30 35 32 12 4 = 195).
4. CA Ideal divides the resulting sum by 11. 195 divided by 11 = 17 with a remainder of 8.
5. CA Ideal subtracts the remainder from 11 (11 ‑ 8 = 3).

Thus, the complete Modulo‑11 check‑digit field is 9434578423.

If the sum of the products is evenly divisible by 11, the check‑digit is 0. If the remainder is 1, the check‑digit is 10. In this case, the data value is not allowable and must be eliminated from the Modulo‑11 check‑digit system.