Post #4334743

@bemmesr@mathstodon.xyz Yeah I guess that kind of questioning approach would be the way to go. Even if you don't find a contradition he accepts, you may find one *you* can see to be there, which may satisfy your curiosity. One thing about Lennes: the reason, I believe, that Lennes adopted the rules he did is that he noticed that the actual mathematical practice was to interpret 1/2a as 1/(2a) rather than (1/2)a. His way of getting this result was to simply say, "do multiplications first" and indeed, that does achieve that result, and that result is desirable. However, it seems plausible to me that in fact mathematical practice was then and is now more complex, at least in its most common form: I think most people interpret 1/2a as 1/(2a), but most people interpret 1÷2×a as (1/2)a. This distinction is the one that gets the most exercise on social media, because most people have never been taught explicitly that the order of operations ought to be different in the two expressions. But here we come up against another of his idiosyncracies: he does not believe there *is* multiplication involved in the expression 2a. So he fails to understand Lennes' position. This one *is* directly contradicted by textbooks, and he has been challenged with that on Lemmy, but he does not accept it