# QR Codes

The QR code has become ubiquitous as a way of sharing digital data on posters, signs and packaging.
The tiny black and white dots are very vulnerable to being misread, and yet QR codes are very resilient.
This activity explores just how resilient they are, and shows an error control method in action.

## Facilitator preparation

- If you aren’t familiar with error control, detection and correction, review the [original related in-person lessons]('topics:topic' 'error-detection-and-correction') (based on product codes and parity error correction).
- In your pre-session messaging to participants encourage participants to have a separate device (perhaps a phone or tablet) with a QR reader app enabled, or a camera that reads QR codes.

This session supports the learning in the following CS Unplugged at a distance sessions:

- [Parity card magic]('at_a_distance:lesson' 'parity-magic') (where students see how extra bits are added to some data, and an error can "magically" be corrected)
- [Binary data representation]('at_a_distance:lesson' 'binary-representation') (where students can explore how just two values (such as black and white) can represent numbers, text and more, using only a small set of cards).

# QR Codes

The QR code has become ubiquitous as a way of sharing digital data on posters, signs and packaging.
The tiny black and white dots are very vulnerable to being misread, and yet QR codes are very resilient.
This activity explores just how resilient they are, and shows an error control method in action.

## Facilitator preparation

- Make sure when you share your screen you also select to share the sound from your computer as this presentation contains a video.
- If you aren’t familiar with error control, detection and correction, review the [original related in-person lessons]('topics:topic' 'error-detection-and-correction') (based on product codes and parity error correction).
- In your pre-session messaging to participants encourage participants to have a separate device (perhaps a phone or tablet) with a QR reader app enabled, or a camera that reads QR codes.

This session supports the learning in the following CS Unplugged at a distance sessions:

- [Parity card magic]('at_a_distance:lesson' 'parity-magic') (where students see how extra bits are added to some data, and an error can "magically" be corrected)
- [Binary data representation]('at_a_distance:lesson' 'binary-representation') (where students can explore how just two values (such as black and white) can represent numbers, text and more, using only a small set of cards).

Add reminder to enable sharing sound in lesson
Add reminder to enable sharing sound in lesson
