A sixth grade Illinois student could feasibly be called a math genius. Joshua Yoon, from Buffalo Grove, scored a perfect 800 on the math portion of the SAT. Many teenaged students who are actually about to head off to college don't ace the math portion of the college entrance exam. But, this Twin Groves Middle School student says he just studied math books to prepare for the test. He and several other students were selected to take the exam after scoring ahead of the curve on a school assessment test. Yoon says he was confident while taking the test but didn't expect a perfect score. Math is his favorite subject but the 12-year-old also likes playing the piano and sports.