<p>Take the GREs or spend your entire personal statement explaining why you didn’t…</p>
<p>and I believe that MIT math funds all its fulltime theoretical math grad students (those who also get outside funding don’t get to doubledip–none of the departments allow that). Otherwise MIT could not compete with the other schools. Like many (not all) of the schools, the funding may come via a TAship or similar arrangment.</p>
<p>If I remember correctly, all the grad depts. require some teaching as part of their program–grad students need the experience and need it on their resume if they are going to pursue an academic job.</p>