The barcode you see on most retail products in the U.S. and Canada is known as a UPC-A, for universal product code, and the number comprises 12 digits. According to Geeky Camel, the first digit ...

One example of this is in barcodes, the sequences of digits we use to identify products. Try it yourself – find an object with a 13-digit barcode. (If you are in the US, a 12-digit barcode will ...