Introduction: Negative Adder (Whats Going On?)

About: I am a person, who like to make things physical and digital. Like many people I like Minecraft, So... I make tutorials on that subject. But I am hoping to make raspberry pi tutorials!

Sooo... I said I'm not good with Redstone and well, I am wrong and well right about that. I want to be a technology expert and I got redstone at my finger tips, so I built a Redstone 4-Bit binary Adder! It works but... The results always appear negative. I Troubleshot it but found nothing, and well I need to know this so I can make a instructable about it.

Step 1: This Is the Adder.

Take a good look at it and try to find the problem, FYI I built this from scratch so that's why there's bugs. What I mean by negative is that off is 0 and on is 1 right? now off is 1 and on is now 0 I did 0001+0001 (1+1) And it said 1101 (Opposite of 0010) (2).