## List of favorite CS Unplugged activities

We have tried all of these successfully in our computing summer camps
• Card trick http://www.csunplugged.org/error-detection - I use a deck of cards for this. Make sure to ask the kids how they think it works and give them time to think about it and make guesses. Have the kids do it as well. Explain how this is related to computers (bits are 0 or 1 like a card is face up or face down). Extra bits are added to transmitted messages to make sure that a bit wasn't lost or flipped.
• Binary numbers http://www.csunplugged.org/binary-numbers - Give them the large cards and ask them to make different numbers like 4, 7, and 15. Ask if there is any other way to make the number. Then have them start at 0 and count up. Have someone record each pattern on the board. Ask if the watchers notice who had the work the most and least. Then challenge them to figure out how high they can count with the fingers on one hand (give the rules that you have to count by 1 and the patterns have to be different - give the hint that it is higher than 5). If they have trouble remind them about powers of 2 and explain that a finger up is like that card showing dots and a finger down is like a card face down. Once they figure out that they can count to 31 with the fingers on one hand ask how high can you count with the fingers on two hands. Explain the general rule that you can count up to one less than then next power of two.
• Paving stones - http://www.csunplugged.org/minimal-spanning-trees This one isn't as active but it is a nice introduction to algorithms. Be sure to not only ask them to find the lowest number of paving stones but also ask what was their process. Explain that to program a computer you need an algorithm - a description of how to solve a problem.
• Sorting networks - http://www.csunplugged.org/sorting-networks - We do this with sidewalk chalk. Use 4 digit numbers so that the participants have to think to do the comparisons. Make each box wide enough to stand in.
• Routing and Deadlocks - http://www.csunplugged.org/routing-and-deadlock - We use color popsicle sticks instead of fruit. We also have colored name tags that each kids wears to let others know what color s/he needs.
• Treasure Island - http://www.csunplugged.org/finite-state-automata - Laminate the cards so they don't get torn. Have a large room or do this outside. Have pencils for the kids to record where each choice takes him or her.
• Turning Test http://www.csunplugged.org/turing-test - Vote on who you think is the computer.