The concept is called "cascading". As for 7VY, Google and Wikipedia will be your best friend for learning these things as there are a TON of concepts to learn to be able to design a computer (in this case, really a "microprocessor" as a full computer would imply all the other peripherals that make it usable). It all starts with logic gates, binary, arithmetic and programming.
you mean bin>dec and dec>bin? @7V7 wikipedia has a good ripple carry adder page
btw piston (de?)multiplexers are really crucial to computers because nearly everything in cpus except the ALU are sorta related to a (de?)multiplexer.
oh, u link the 2s digit of the full adder output to the carry input digit of the next full adder.
how do i link multiple adders together
BTW to subtract numbers, you should just invert one of the input numbers, and the output.
Im sorry, i didnt know that when i uploaded it. Im working on what NoVIcE said
this definitely is at most a full adder, not a computer though, isn't it?
Update: Finally managed to make a full adder that is compact and works every time. I had to do some math with spark timing.