Off-topic but related: If you are studying engineering or medicine or any field where there will be a significant penalty in money or harm to others of mistakes

Off-topic but related: If you are studying engineering or medicine or any field where there will be a significant penalty in money or harm to others of mistakes, DON'T settle for an A. Learn (practice) to get the right answer when working problems. In the real world there are no answers in the back of the book, and even when someone else is backstopping your work they can miss mistakes, too. Take the time when doing a problem to make sure you understand it and if it's complicated don't try to keep track of everything in your head.