and TEACH ME THE PROPER ORDER OF OPERATIONS.
So I never heard of this mnemonic until today when a math teacher buddy of mine shared it.
I had decided to teach my niece about order of operations, seeing as how she said "Hours of operation?" when I asked her if she had heard of it.
Anyhow, I came to a problem when I realized that 3÷3*3 is either 1/3 or 3, depending on which operation you do first. I was like "damn, is there a rule for that?"
Like, in practice it never comes up since you likely won't see a division sign in college and the fractions make the division completely obvious as to when it happens.
Anyhow, I looked it up, and with a chain of division and multiplication you just do it left to right. That's fine, it makes sense. Cool.
Then my math teacher buddy gets back with the "Please Excuse My Dear Aunt Sally" mnemonic, and I was like "wtf that's wrong." And then he pointed out that you then have to say that multiplication and division are the same (my feeling as well) and subtraction and addition are the same (agreement here), and in those cases you just do it left to right.
Anyhow, I think that this mnemonic is retarded since there are only 4 classes of things and that's trivial to remember anyhow. Parens, exponents, multiplication, and addition are all we need to talk about. PEMA. Please Excuse My Aunt, if anything. Then Equivalent operations are done left to right, and multiplication is equivalent to division, which is not tough to explain since it's just a multiplication by the inverse, and subtraction is the same as addition - just adding a negative.