Sorry I didn't explain, and I know it is a bit off topic, but I thought I would show what I am working on. First off, please learn up on base two, as I don't want to give a math lesson. It's a pretty simple concept, and it can be applied to all other bases. A computer uses base two, so it is important to inderstand before further explanation. So, onto the most basic kind of adder. A one-bit half adder is exclusively for adding two one-bit numbers. A one-bit number in base two is either a zero or a one. These two numbers are represented by the two inputs, A and B. The outputs, S and C, represent the three possible solutions. These consist of zero, one, or two. Two is written as 10 and represented by C being powered. One is represented by S being powered, and zero is represented by neither S nor C being powered. Confused? We're just getting started! A one-bit full adder is very similar to a one-bit half adder, except for one difference. Instead of just A and B as inputs, it also has C, which can come from any other adder, allowing not just two one-bit numbers to be added, but two! And 3! And n amount of one-bit adders there are bit numbers. In other words, if one has four one-bit full adders , or at least 3, with a half adder, two four-bit numbers can be added. The first adder adds two one-bit numbers, for a maximum of two with no input. If it gets one, it powers S, representing the total number of 2^0s in the sum. If it gets two, the result is carried on as C to be added with the next two one-bit numbers. But these are no ordinary one-bit numbers; they each represent two! A sum of one is output as S, but it actually represents two! Can you guess what happens next? If it gets a two, really a four, it is carried on as C to be added with the fours, each represented by a one- bit number. S represents four. On the top deck, the eights are added. The final sum can be modeled by: A0*2^0+A1*2^1+A2*2^2+A3*2^3+ well... the same thing for B. Can you figure out what all of this means?
This might help.
-Highrise