PRO Number Check-Digit Formula

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.

Example: XXX-XXXXXC (PRO number)

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:

Check Digit	Remainder
0	.00
1	.14
2	.28 or .29
3	.42 or .43
4	.57
5	.71
6	.85 or .86

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