There are only 10 types of people in the world: Those who understand binary and those who don't!
One of the fundamental computer science concepts is that everything we do on a computer really comes down to just two numbers: 1 and 0. All data, no matter if it is text, music, videos, or something else is represented by a multitude of 1's and 0s'. Just like when a light is switched on or off, the circuits in a computer are either in an on/true (1) state or off/false (0) state. Even though this sounds simple, it can be a concept that is hard to wrap one's head around. Here are some activities to introduce students to the concept of binary:
Check out the CS Unplugged Count the Dots videos & activities. This helps demonstrate how binary numbers works.
Try your luck at this Binary Game or that Binary Game.
Create an account on Scratch and then go to Makey Makey Binary Switch I.
Select See inside code and then Remix.
Select the Stage and see a variable called switch.
This is what will turn the animation on and off (1=ON and 0=OFF).
Do you see which keys correspond to ON and OFF?
Select Sprite1. See that when the variable switch is set to 1, the sprite moves forward.
When switch is set to 0, the sprite stops moving forward and it waits for you to switch it on again.
Notice the code is checking forever whether the switch is set to 1, then it is performs the ON code, else it performs the OFF code.
Create a ON / OFF switch with your Makey Makey kit. Remember which key is ON and which is OFF? You'll also need to complete the circuit, which means you must be connected to the ground wire in some way (I'm a fan of the tin foil bracelet, except when it itches;-).
Try remixing the Scratch project to add sound that will turn on and off using the same switch variable.
Add another sprite and have its movements turn on and off using the same switch variable.
How many different On / Off switches can you design with for the Makey Makey?
What happens if you reverse the switch?
Can you use just one input key to switch between on and off? Have you ever heard of The Clapper!
See MaKey MaKey Binary Switch II for more examples.