Logic Gates and Full Adders

Greetings /prog/

I admittedly haven't been here before, haven't even been to this site but I was lingked here from /g/ so... I was wondering if you could give me a hand with something. I'm a first year computer science student (I know I know there's no jobs and it's a waste of time and whatever) and I was looking through some past papers when I came across a question that has me a little perplexed.

The question asked how I would go about building a denary full adder using these logic gates in order (XNOR,NOR,NOT,NAND). Now logic gates and all that related shit are my arch nemesis but I have no fucking clue how this would even work. Is this somethign that's trivially simple and I'm just being dense or is this as puzzling as it seems?

Sorry if these kind of questions are taboo or whatever, I wasn't willing to lurk for a few months before asking.

>>38
The details of the inside would be nice. I'm still confused as to how this works from a circuitry standpoint.

Do you use a regular full adder 4 times, effectively adding the denary numbers together? How do I make it so that it knows that the number is above 9... like... if...

A and B and C and D
A and B and !C and D
A and !B and C and D

Are all the combinations that I think can give you a binary number equivalent to >9 so would I have to wire it so that those states result in a carry. Also what if what I get results in a carry of greater than 1? Like 1111 + 1111?

Looking back this shit is a hundred times more complicated than anything we were taught or I'm just not understanding something.