Below are two QR codes. They are a bar-code type link to websites. We are using them in class to research  two areas of interest. Yesterday we were discussing the alphabet and students had questions such as, "Why are there 26 letters?", and "Why is it called an 'alphabet'?", and " Why do we have an alphabet?"
So, I used the KIDREX search engine (linked on our class blog) to locate some useful websites, copied the URL into the QR code maker, and it gave our a QR code, as below.

Students are also interested in the flags of students from our class, and wondered why a particular flag was a particular colour and design. So, off we went to the search engine and QR code maker.

Below are two examples. In order to access the QR codes, you need a QR code reader. We use our Ipads and the app  i-nigma ( see image of app below). So, if you have an Ipod or Ipad, give it a go.