Argument: You need to get to bed early. You have two midterms tomorrow.
Analysis: The unstated premises that needs to be stated for this to be a valid argument would be, “Getting extra sleep can help you focus better and do well on tests”. Also, it would help if the word “need” were changed to “should”. The only thing that is absolutely true is that fact that you have two midterms tomorrow. Another thing that could be added would be the statement that you do indeed want to do well on your midterms. However, this is such an obvious standard that it does not even need to be stated in order to be understood. Even without all of this extra add-on stuff, this argument is OK because the premises is more believable than the conclusion, and there is that one major unstated claim that you do want to do well on your test. Assuming that the reader assumes this, the argument is believable even before repair, but better with.