180 Appendix D

The control digit is an internal control used to eliminate the processing of transposition errors by automatically rejecting input which is not valid. The control digit is system calculated for all openings. The control digit is computed as follows:

It is based on the assigned case number, which is comprised of three basic parts:

The County Number is assigned by arranging the counties alphabetically and numbering 1 through 67. For counties 1 through 9 only, a zero is placed in front of the number (01, 02, 03, 04, 05, 06, 07, 08, and 09).

At the present time, Record Numbers are comprised of three to seven numbers. The number of characters in the Record Number is extremely important in the calulation of the check digit for the following reasons:

The letter(s) of the alphabet used to indicate category must be changed to a number.

The table below shows what number will be substituted for category for check digit calculation:

OAA = 1	BPB = 2	AFDC = 3	GA = 4	ADJ = 5	BPM = 6	TANF = 7
A	B	C	D	J	M	U
PA	TB	PC	PD	PJ	PM	PU
TA	N	TC	TD	TJ		TU
			K
			PK
			TK

Following is a step-by-step calculation of a control digit for Philadelphia County (county number 51), Record Number 685847, for a second TANF recipient in a household in a nursing home. Thus, the case number for this example would be:

Even though for each step in control digit calculation the number is rewritten, in the actual calculation it is only written once. Below are the steps used in calculating the check digit:

	County Number	Record Number	Suffix
Step 1 Set down the Case Number with only the first letter of category.	51 51	685847 685847	C2 C
Step 2 Change the letter of the alphabet indicating category to the appropriate number from the table on page 1.	51	685847	3 (C changed to 3)
Step 3 Determine whether the Record Number portion has an even or odd number of numbers in it. If the Record Number has 2, 4, or 6 numbers in it, precede the Record Number with a zero. If the Record Number has an odd number of numbers, do not add a zero.	51	0685847	3
Step 4 Starting at the right-hand side of the number, divide the numbers into groups of two.	51/06/85/84/73
Step 5 For each one of the five groups of two, go to the Control Digit Generation Table below and find the two numbers. Take the single number appearing to the right of the two numbers within the specific block and place it beneath the group in the Case Number.	51/06/85/84/73 3 / 7 / 1 / 4 / 7	1^st Group – 51 on table – 3 2^nd Group – 06 on table – 7 3^rd Group – 85 on table – 1 4^th Group – 84 on table – 4 5^th Group – 73 on table – 7
Step 6 After the groups of two have had their weights assigned or converted from two numbers to a single number from the Check Digit Generation Table, add them across.	51/06/85/84/73 3 / 7 / 1 / 4 / 7 3+7+1+4+7 = 22
Step 7 After the addition, the check digit is the right-hand number of the result of the addition. Thus, for this pseudo Philadelphia Case Number, the check digit is 2 (two).	51/06/85/84/73 3 / 7 / 1 / 4 / 7 3+7+1+4+7 = 22

Control Digit Generation Table
00-0	10-9	20-8	30-7	40-6	50-5	60-4	70-3	80-2	90-1
01-8	11-7	21-6	31-5	41-4	51-3	61-2	71-1	81-0	91-9
02-6	12-5	22-4	32-3	42-2	52-1	62-0	72-9	82-8	92-7
03-4	13-3	23-2	33-1	43-0	53-9	63-8	73-7	83-6	93-5
04-2	14-1	24-0	34-9	44-8	54-7	64-6	74-5	84-4	94-3
05-9	15-8	25-7	35-6	45-5	55-4	65-3	75-2	85-1	95-0
06-7	16-6	26-5	36-4	46-3	56-2	66-1	76-0	86-9	96-8
07-5	17-4	27-3	37-2	47-1	57-0	67-9	77-8	87-7	97-6
08-3	18-2	28-1	38-0	48-9	58-8	68-7	78-6	88-5	98-4
09-1	19-0	29-9	39-8	49-7	59-6	69-5	79-4	89-3	99-2

Record No. (Even Number of digits)	Record No. (Even – Preceded by “0” for calculation of control digit)
685847	0685847
579831	0579831

Record No. (Odd Number of digits)	Record No. (Odd – for calculation of control digit)
43761	43761
875	875

County Number	Record Number	Category (or suffix)
00	0000000	000

Appendix D: Procedure for Calculating Control Digits