Bar codes hide an ingenious sum of control in a surprising mathematical formula.
Sometimes there is hidden patterns In the numbers we do not immediately realize. An example of this is the Bars codes.
Find an object with a 13 -digit barcode.
Add the first, the third, the fifth, the seventh, the ninth, the tenth and the thirteenth digits, to obtain the sum of the odd digits. Then add the even digits. If the sum pair and then add to the original odd sum, the total should be a Multiple of 10.
Let’s test with the photograph code above represented: 5+0+3+4+5+0+0 = 17. (2+1+1+2+5+0) x3 = 33. 17+33 = 50, which is multiple of 10.
It is no coincidence. As Mathematics explains Katie StecklesIn an article recently published in, barcodes contain a sum of verification, ensuring that when read, it is read correctly.
Most digits serves to communicate information – such as so many fields.
The first three digits of a barcode serve to represent the country where the code was originally issued. 560 It means that it is a product produced in Portugalfor example. The following 10 digits is more specific information about the product and who produced it.
Bar code readers use, in turn, lasers to capture the standard of stripes, which encodes the same numbers. In a supermarket, for example, they read the digits, calculate the sum of verification and only emit a sound signal if it is correct – and until you get a correct reading, it does not accept it.
Even so, This system does not fully eliminate errors. In the case of barcodes, there is a probability of 1 in 10 of the sum of control resulting in a multiple of 10, even if there is an error.
In addition, readers also do not say what the error is. This is why it is often experienced scanning the number again. Still this system saves time that would otherwise be wasted to try to process incorrect numbers.
