I read it then went off to try and do some work and then got kinda lost in that. haha
Anyway - I think that I get it, but what was the purpose of numbering C2 like that in the first place when we're actually assessing the weights of the Carbon groups bonded to it? Also, why start with C2 rather than, say, C3? And why don't we could C2 as being something that C1 and C3 bond to? Although I guess it wouldn't really matter since they'd just cancel each other out.
Sorry, lots of questions haha. Thanks a lot by the way!