So much more than scale, volume and area

Initially I thought the only thing I could use Minecraft to and connect to education was math. But hey, it's so much more than scale, volume and area! Despite the fact that every wiki is on English (language and ICT) there's really no limits. You can do whatever you want, only your imagination and creativity puts the limits.

I have a couple of students that happens not to be out on work practice, instead they should pass old courses. But, again, the power of Minecraft is so much bigger than school. I thought I had to bring them back to track, to construct something inside Minecraft so much interesting they don't want to continue play. And I thought for myself it will take lots of times to fulfill my challenge.

Well, they did start to solve my challenge, but they did it way too quick and are now back playing survival mode. What was my challenge? Well, I wanted them to figure out how to construct a calculator. I also thought for myself, I guess they have to search and look a couple of YouTube clips before they can start build. I also thought they have 2-3 weeks of work there. Nope, I guess, from nothing to ready they have spend like 1 course/24 lessons on this challenge. And they also both have different solutions! 

They did the constructions all in their heads without any input from a tutorial. They didn't had to since they already had figured out how redstones and command blocks works. I was so amazed when they showed me and the calculators didn't work properly and they immediately started to debug their systems...

The redstone calculator and according to @abrightmore it's electrical engineering (boolean logic, signal strength, toggling states and more) was made like this:

I got very impressed about this calculator because the student who made this, of course he's smart, but I din't expect a redstone calculator from him. And he had some problems getting it started (self confidence) but debugged it and solved the problems while he explained what everything do. This calculator could handle digits up to 100 and return the answer in the scoreboard. 

The other calculator was even more impressive, even though it was made with command blocks (I was expecting redstone solutions). The other guy had made an impressive screen, with digits on a screen (sort of). Then he took me underground and I lost my breath. Lots and lots of command blocks! And he's been doing it with the command block knowledge but without any calculator tutorial! I'm impressed! And I also realized I'm not 20 anymore :P