Mutiple Choice Tests
What happens when you don't know how to answer the question? Since one of the answer choices is the correct answer, try working backwards to find the correct answer. This is the reason also for reading the answer choices before starting to answers or solves the question.
Learning new material in a class is much like learning a new sport or hobby. For all of these, you must practice and keep up your skills so that they don't be rusty or less confident. Much like famous basketball players staying after practice to shoot 100 free throws to improve his shooting percentages, so do you need to practice, study, and re-write the important steps to solving out math problems? But wait, the basketball player didn't just shoot 100 free throws then go home; he had to 100 free throws in a row before going home. Do you have similar expectations for yourself in math and your other classes?
Short Answer Test
to become more successful at these types of tests and questions is to re-read your math steps and essays before turning in your test. Many "little" mistakes can be caught when reading through your work.