QR Codes 

http://mal-den-code.de

QR codes can be used in many ways at school. With this website, you can create color QR codes that are great for a quiz or contest.

What is behind the quadratic codes? 
What are QR codes for coloring?

QR codes are related to the classic barcodes (barcodes) that we can find on virtually all product packaging. For example, in retail, the EAN-13 barcodes are very common:

Such a barcode can be scanned by appropriate readers (for example, at the point of sale in the store). The reader calculates a number from two lines and two free spaces. So that we can also read the number so encoded, it is printed below it again. The scanner beeps if successful and sends the read number to the connected computer:

4 780201 37962 9

The last digit will not be sent. It is not part of the encoded information but serves as an additional number to check whether the actual number has been read correctly. For this, the first part of the long number is used to form the checksum and each digit is multiplied by either one or three, always alternating:

1 4 + 3 7 + 1 8 + 3 0 + 1 2 + 3 0 + 1 1 + 3 3 + 1 7 + 3 9 + 1 6 + 3 2 = 91

Now the difference to the next tens is calculated from this sum. So in our case the one hundred. 100-91 = 9 . This guarantees a one-digit number. Only if this number coincides with the additional number in the barcode, reading has worked. If the scanner does not beep at the cash register, it may be because the black bars were not recognized correctly and the check of the additional number fails. Often it is then enough to spin the code a little, to smooth wrinkles in the packaging or to draw the code as straight as possible.

QR codes

The QR code works much like a barcode. Instead of lines, however, he uses small boxes in a two-dimensional pattern. In a square code fits much more information. Instead of a single number, for example, we can wrap an Internet address like http://mal-den-code.de in it. As with the barcodes, there are also additional elements in the QR code with which reading errors can be detected and even corrected. One speaks of redundancy and error correction. Most QR codes have a redundancy of about 25%. This means that even if a quarter of the QR code is destroyed, the information can still be decrypted with the rest. Even the right code still works, try it out:

A QR code always has three big and one small conspicuous square in the corners. These serve the scanner for position detection. The scanner can calculate from where the code starts and where it ends. The small square is used to determine the direction. This indicates whether the code is upside down or tilted to the side. The remaining dots encrypt the information.

For coloring

QR codes are also great for quizzes or competitions. For this purpose, a part of the code is left blank and provided with numbers or letters. You print this incomplete code on paper. At least enough to read the characters well. The players now have to complete the middle part with a dark pen. Only those who paint the right boxes can then scan the code and get to the deposited website. Here's an example:

QR-Code for coloring

And this is how it works: You are thinking up exciting game questions. Depending on the answer, the players should paint a number or a letter on the board. For example:

And this is how it works: You are thinking up exciting game questions. Depending on the answer, the players should paint a number or a letter on the board. For example:

Is the earth a ball?

yes - then draw all the ones out

no - then draw out all fours

Of course, only you know which letters and numbers have to be painted. Always download the solution sheet after creating it. At the very bottom of the solution code are also the correct and wrong characters listed. You can do this when writing down your questions so that you do not forget them. Depending on how many questions you want to use, select a different difficulty level when creating the QR code.

Have fun creating the puzzle :-)

Create code

Create your own QR code. All you have to do is enter an Internet address to which your code should lead: