<p>I memorized enough prime numbers at an early enough age to get past what is, after all, always a multiple-choice question that I don't see there is any real concern here. People who want to impress an admissions officer with math scores use the AMC</a> tests anyway. </p>
<p>P.S. I have coached an eleven-year-old to an 800 on the SAT I math section (with some help from math teachers I helped find for him, of course) so I'm really serious when I say that this tip overstates its usefulness.</p>