This is my second academic day in university (1st academic day is when the first class starts). I have some question, in which your opinion would be welcomed! 1) Sound Volume: A female lecturer talked with a very low volume. I already asked her to speak louder. She said "OK, I'll speak as hard as I can". But she still spoke softly. Is it ethical for me to ask again and again for a louder voice? 2) Minor Mistakes: When people write in the whiteboard, sometimes they make minor mistakes, like typos (for example "the fumction g(x)...". Is it OK to point out and say "Mam, you did a typo there...". How about when people forget to write an arrow above a vector's symbol ("Sir, you forgot to mark that as a vector"). 3) Use of Language: "Why do we need to mention the commutative property of real number multiplication? Because not all elements in the universe have that property. Matrix is one example of that.". What if I said "Mam, matrices and real numbers are not elements in the universe. Gold is one such element."? OK maybe not that rude, but should I tell her that her use of language isn't appropriate IMO, or should I just live with it? 4) I pointed once "Mam, you forgot to mention/write that n cannot be zero (a theorem involving m/n)". Afterwards she said "It is understood that in real number divisions the denominator isn't zero". My textbook writes "d isn't 0" in every division problems where d is the denominator, so I felt uneasy with my teacher's convention. Should I live with it? Well, you guys get the idea. I'll wait for any number specific answer or general advice. Thanks a lot!