When an opportunity arises JUMP IN!!!!
Imagine this...two students eating lunch, get talking about what they brought for lunch and how it was bought at the supermarket.
The teacher starts paying attention to the conversation. The next thing she knows one is saying:
"- so the woman at the cashier passes the food on this rectangle that goes beep and this appears on the computer, like magic!"
I jumped in immediately... and explained that she is passing the food over a scanner that translates the barcode on the food for the computer.
We looked for barcodes on their food, and then on their boxes of apple juice, and then we found them on books! Soon, all the children were looking for things with barcodes.
So, the next morning, there were 2-D barcodes (specifically, QR codes) posted at various places around the school. I had downloaded an app onto the class iPad, and the children were able to scan the codes to read them. Of course, I had printed the codes the previous evening, and they contained fun messages for the kids to read! (Yes - to read. Sneaky, isn't it?)
Next step: coded math puzzles!
You never know when the kids will get curious about something, but when they do, it can be amazing how much fun - and learning - you can get out of it!