# Last number in barcode [closed]

Find solution, how work algoritem for last, control number in 8 places barcode. Here is some results:

1. Here we got last number 8 2. Here we got last number 7: 3. Here we got last number 5 What is last number of this 2 Barcode?

and this

Try multiply some numbers with 3

• Finding industry barcode algorithms is not a puzzle. – Deusovi Mar 5 '16 at 22:36
• I'm voting to close this question as off-topic because it's not a puzzle. – Deusovi Mar 5 '16 at 22:43
• I have a feeling that if the answer wasn't publicly available information, the three examples given would not have been enough to figure it out. – f'' Mar 5 '16 at 23:16

The barcode checksum is derived through the following process:

1. Add the digits at odd positions, then multiply by 3.

3. 10 minus your result, modulo 10, is the check digit.

So for the first one: $10 -( ((5+1+4+8)\times3 + 1 + 8 + 3) \mod 10)=7$

And for the second: $10- (((5+0+2+4)\times 3 + 7 + 1 + 3 )\mod 10) = 6$

• You have right, but only first one you write 1 not 0. – neiiic Mar 5 '16 at 22:42

Pretty sure its:

1. 5

and

2. 0

Just by looking at previous numbers.

• @Deusovi why did I get a downvote for answering? – Z. Dailey Mar 5 '16 at 22:37
• Because this answer is wrong. – Deusovi Mar 5 '16 at 22:38
• Someone needs their 886609 546***. Sheesh. – Z. Dailey Mar 5 '16 at 23:04
• You need to provide justification for why you think the answer is correct. "Just by looking at previous numbers" is not helpful. – f'' Mar 7 '16 at 5:19
• Yah. I didn't assume it was necessary after it was pointed out to be wrong and the right answer was already posted. I looked at the section of the barcode over the blank space and attempted to match to a known number. – Z. Dailey Mar 7 '16 at 5:24