One of the fundamental computer science concepts is that everything we do on a computer is really just turning binary digits on and off. Even though this sounds simple, it can be a concept that is hard to wrap one's head around. This activity brings the binary concept to reality through the creation of binary bracelets.
Perler beads
Thick elastic cord
Print outs of the K-2 or 3-5 Binary worksheet for each participant
Pro tip: if you have limited time, pre-cut lengths of elastic cord and double knot on one end. Pack that along with Binary worksheet into zip lock bag ahead of time. Girls can then also package up their beads if they run out of time.
Don’t have access to supplies? Have students create a binary bookmark instead.
Check out the activity instructions on GoOpenVA.
Ask what makes a computer work? Eventually, someone will mention electricity or power. Talk about how we turn lights on or off. Because a computer is built on electronics, that's all it fundamentally understands - on or off, 1 or 0.
How do humans communicate with computers? We don't speak 1s and 0s. Show how we can use binary (base 2) to add up to decimal numbers (base 10) by turning the binary code on (1) or off (0).
For a while, the only way humans could communicate with computers was with numbers, but now we can use words and code. To do that, a group of folks got together to agree to a standard called ASCII, assigning letters to numbers. You are going to take the numbers associated with your initials or a 3-letter word and create a binary bracelet.
Ever seen a binary clock? Not so simple to read for humans (at least not this human).
If you have 10 minutes & are working with middle schoolers or older, Crash Course Computer Science: Representing Numbers and Letters with Binary video has a great explanation.
If you are working with younger students or only have 5 minutes, then Count the Dots from CS Unplugged is a good option.
If you need to go unplugged, then Binary Baubles from Thinkersmiths (pages 18-21) provides the info you need to explain binary & this activity.