Need a formula to calculate a MOD10 check digit for a string of 26 numbers.

[Artkrum4th]

Hello! I have tinkered with some formulas I found on the interwebs but they are not producing the resulting digit that passes the cager's validation (this is for a fundraising mailer). I am at my wits end! I can convert alphas to numbers, so I do not need that part.

Here are the requirements:

Mod-10 Check Digit Routine​

Example

Scanline: 40290350 HDS1114 12



4 0 2 9 0 3 5 0 H D S 1 1 1 4 1 2



Alphas Converted: 4 0 2 9 0 3 5 0 8 4 2 1 1 1 4 1 2

Weights: 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2

Products: 8 0 4 9 0 3 10 0 16 4 4 1 2 1 8 1 4

Sum of Digits: 8 + 0 + 4 + 9 + 0 + 3 +1+0 +0+ 1+6+ 4 + 4 + 1 + 2 + 1 + 8 + 1 + 4 = 57

Modulus 10: 57 % 10 = 7 (modulus returns the remainder of 57 divided by 10)

Complement Remainder: 10 - 7 = 3 (subtract the remainder 7 from 10)

Check Digit: 3

 

[Artkrum4th]

Here is an example of the cager's corrected check digit for one of the records:

# 1 Moody

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Scanline w/o Check Digit

0​

0​

3​

J​

0​

0​

0​

0​

0​

1​

8​

Q​

Y​

B​

L​

A​

A​

4​

2​

3​

T​

F​

H​

6​

H​

G​

CD is pre-printed as 7​

Convert Alphas

0​

0​

3​

1​

0​

0​

0​

0​

0​

1​

8​

8​

8​

2​

3​

1​

1​

4​

2​

3​

3​

6​

8​

6​

8​

7​

Assign Weight Pattern (2 1 2 1)

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

2​

1​

Multiply

0​

0​

6​

1​

0​

0​

0​

0​

0​

1​

16​

8​

16​

2​

6​

1​

2​

4​

4​

3​

6​

6​

16​

6​

16​

7​

If product was 10 or above, sum the two digits

0​

0​

6​

1​

0​

0​

0​

0​

0​

1​

7​

8​

7​

2​

6​

1​

2​

4​

4​

3​

6​

6​

7​

6​

7​

7​

Subtotal

91​

Divide by 10

/ 10​

Quotient

9.10​

Subtract the remainder from 10

10 - 1​

Check Digit

9​

 

[Georgiboy]

On the row: If product was 10 or above, sum the two digits

How are you getting 7 from the numbers: 8, 2 and 16