One of the ways that Minecraft is changing the way that I teach is by providing more tangible ways of explaining abstract concepts. For example, one of the topics on the AP Computer Science curriculum is the idea of logical operators in boolean algebra. An example of this is the AND operator.

Simply put, the statement **if (x > y AND y > z)** only evaluates to true if x is greater than y and y is also greater than z. In class, this has largely been a pencil and paper exercise. Yesterday, I showed my students the equations on the board, and then I showed them a few simple logic gates in Minecraft that I built with redstone, levers, and sticky pistons.

I cleared out the weeds from a flat area near the World Map building, and built a couple of structures out there.

This is an AND gate. It only extends the piston when both levers are flipped.

This is an OR gate. It extends the piston when either one, or both, of the levers are flipped.

This is an XOR gate. It only extends the piston when one, but not both, of the levers are flipped.

The assignment for my kids is to go through this Redstone Logic Gates guide, and to build a few of these circuits in single player creative mode. Then, they need to do the following:

- Using redstone, create a logic gate that does something useful for your home or learning commons.
- Post a short video (1-2 minutes) in the Discussions area of our CMS that shows the redstone and explains the logic gate, how it works, and what it does that is useful.
- The logic gate can be one of, or a combination of: AND, NOT, NAND, OR, XOR, NOR, XNOR, or Implies.

This is a video challenge I issued to my high school students to build something using redstone. It's an introduction to logic gates, and a challenge to build something original incorporating some of these principles.

I like the idea that this is applicable to the real world, as well as Minecraft and the AP exam. In my house there is a hallway with a light switch at either end. Both light switches control the same hallway light. Each switch has an ON and OFF setting. It's always puzzled me that sometimes in order to turn the light ON, you need to flip the switch OFF, depending on who last used the switch.

This is a puzzle that can be expressed using boolean algebra, and modeled in Minecraft.

Here is an example of a project one of my students created.