I have seen online these diagrams for 4-bit adders which feature 4 individual full adders chained together with the carry out from the previous feeding into the carry in to the next.. Likewise, to add 8 bits, they would require 8 full adders. Presumably, for a 64 bit computer, you would need 64 full adders.
I know there are many different types of adders which may potentially solve this problem, but I'm talking about the basic full adders you see in a school textbook - if you wanted to do 64-bit addition, would you need to have 64 full adders together?
I'm also curious how many adder circuits a typical modern desktop would have - I mean, I see videos featuring components like this (https://www.amazon.com/4-BIT-BINARY-FULL-ADDER-DIP-16/dp/B00E4WLIWE), and, as far as a I can tell, this is a single, 4-bit adder. So if you have a couple of cm for a single such device, a computer would only be able to have a few dozen or so, but is this typical, or would a computer have millions of adders?
In this case, are these circuits you can buy online only 'huge', so that they are practical to work with for human hobbyists using breadboards as opposed to, you know, robots who manufacture stuff for commercial products, who can happily create millions of adder circuits on probably the than the size of your fingernail?
If anyone could clear any of these points up for me, I'd appreciate it.