|MOD 7 Check Digit - The check digit is the last or ninth number of the PRO number. The first eight numbers are in sequence.
The check digit, or ninth number, will be 0 through 6, and will never exceed 6.
C = Check digit
|The check digit is determined or verified by dividing the first eight digits by seven. The remainder of this division is the check digit.||Examples:
Using a calculator, divide the PRO number minus the check digit by seven. The decimal remainder will determine the check-digit number.
The following table shows the check digit of each decimal remainder when dividing by seven: