 Computer Science Unplugged is a free collection of activities that expose students to ideas from computer science without using computers. This removes the barrier of having to learn to program or even own a computer before you can find out if computer science is your thing. Computer Science Unplugged uses kinesthetic activities that enable young students to physically engage with concepts, like this parallel sorting network where students follow a simple rule comparing numbers when they meet at a box and ending up in sorted order. After doing the physical activity, they can explore the concepts through discussion and exercises. This activity can be done by a group of six students or a whole class. Another activity is the card flip magic trick, which is a memory trick that impresses students of all ages. It's based on a forward error correction code that children can usually figure out for themselves. And again, once they have understood the concept, there are many variations and questions to explore. Binary numbers can be explored using just a set of cards which provide the scaffolding to convert numbers and find patterns in this black and white number system. There's even a pop music video where messages are coded as binary numbers into the tune and the dancing. There are many algorithms to explore. In this case, students use balance scales to compare two identical looking weights at a time in order to get them ordered from lightest to heaviest. Binary search and the idea of dividing conquer algorithms can be explored using ping pong balls hidden under cups. Computer science unplugged has several activities about encryption, especially how secure communication can happen on an insecure network. The resources also include a picture book where Santa uses a divide and conquer algorithm to find a pair of dirty socks that has been accidentally wrapped up with a gift. Image representation is explored with oversized pixels and students can press them for efficient transmission. Like most of the activities, there are paper-based exercises to follow up, as well as a growing number of computer-based activities. There are many more activities, including getting familiar with the concept of finite-state automata by running around the playground and exploring issues of routing and deadlock using fruit. Computer science unplugged is used in many countries around the world and even in virtual worlds. It is supported by a team of international translators, advisors and advocates. It has been translated into many languages and the resources and text are freely available for teachers and presenters to adapt for their own context. Computer science unplugged is about empowering students to explore the great ideas that are hidden in the technologies that have become so commonplace that they are taken for granted. But most of all, it provides an easy and fun way to engage with students around the topic of computer science.