Dr P
” it seems as if different textbooks teach the order of operations differently.”
This hasnt been my experience. And today although people calim there are nobody has ever been able to identify these alleged textbooks (although IVe asked)
I think people (myself included) forget the order of operations (most of us havent done these kind of problems in decades) So we get the question wrong. Then when reminded we feel silly that we got an elemntray school problem wrong.
Instead of saying “” wow cant beleive I forgot the rule” The responses are “There must be other rules” “the rules are made up its up to each person if they should follow them ” etc (these arent verbatim quotes from this thread)
“(I can not recall seeing a textbook that gave an order of operation that would yield a number other than 1 but from Google searches it seems like there are.)”
I could not find any such rule for order of operations. (a few posters said “PEMDAS is a convention, not a hard and fast rule.” and “Following the system where multiplication is deemed a higher order operation than division:” These are verbatim quotes. and not based on any thing real
BUT
however I did find some debate over Flaming’s Pitfal #2 with some fellow (who seemed well reaosned) arguing that 8÷2(4) was not the same as 8÷2×4 (which would absolutly be 16) rather that 2(4) was one unit equaling 8 (thus leaving 8÷8 = 1) not two seperate units 2×4 (which would require first dividng the 8 by 2)
For interesting sources see Slate’s “What Is the Answer to That Stupid Math Problem on Facebook?
And why are people so riled up about it?” (3/12/13) where he argues (wrongly in my opinion) “none is incorrect.” the thrust of the article is that histoically there are different ocnventions, and sure in 1919 a different answer may have been correct but that has no bearing on today.