Yeah I think this is more about how you interpreted it, because it doesn't look like others took it as being an absolute magic trick rule and neither did I.
The Panzer of the Lake didn't use the word "commutativity" (fuck that really is hard to spell), but it gave out some wisdom that applied that rule by saying that "percentages are reversible": if the reverse of a percentage would be easier to calculate, you can use it and get the same answer. If it's not easier, well, then you're screwed ๐ Oooooor depending on the situation you can use the a ร b% = a ร b / 100
commutativity trick:
7 ร 8% = 0.56
7 ร 8 / 100 = 0.56
You're welcome! Glad I could give you an a-ha moment.
Having an intuitive feel for tricks like using the definition of operators or symbols to make your life (well, calculations at least) easier usually means that you either have to just be "naturally" talented at math which is really rare, or you've just had to grind grind grind math at eg. university, work or whatever. So unless someone was taught that above trick and they actually remember it from school, they might never come to think that "hmm % just means
/ 100
so that can make this easier to figure out in my head".