Guess the Bar Code - Amaze your friends! (Just for fun!)

How to Read 12 Digit UPC Barcodes

Most bar codes in the US are 12-digit UPC (Universal Product Code) barcodes, with ten digits at the bottom of the code and one small number to each side. Impress your friends by asking them to select a random item from the kitchen with a removable label and cut the numbers off of the UPC barcode; you can then proceed to read the numbers encoded in the lines.

Steps

1. Note that barcodes are made up of both white and black lines. The white spaces in between the black lines are part of the code.
2. Understand that there are four different thicknesses to the lines. Henceforth, the skinniest line will be referred to as "1," the medium-sized line as "2," the next largest line as "3." and the thickest is "4."
3. Each UPC barcode begins and ends with 101 (thin black, thin white, thin black). In the very middle of the barcode, you will notice two thin black lines sticking down between the numbers. The thin white between them, as well as the thin whites to either side, make up a 01010. Each UPC barcode has 01010 in the middle.
4.  
5. Recognize that each digit, including the small numbers that begin and end the barcode, has its own unique four-line set. 0 = 3211, 1 = 2221, 2 = 2122, 3 = 1411, 4 = 1132, 5 = 1231, 6 = 1114, 7 = 1312, 8 = 1213, 9 = 3112. (Note that the sum of bar widths numbers is 7 for all codes because each code is 7 units wide.)
6. So, the barcode above whose first two digits are 03 would start out "10132111411". Broken down this is "101-3211-1411" where 101 marks the beginning of the bar code and 3211 marks the digit 0 .

For tips and tricks GO HERE

As for the Ethics of deciphering coupon/item codes: GO HERE (WOW is this an interesting read!!!!)