Douglas Platt is currently a full time doctoral student and research fellow at Montclair State University, in the Mathematics Education doctoral program. He is working on his dissertation on teachers’ mathematical knowledge of the minus/negative sign. He holds a master’s degree in mathematics from MSU, and has taught mathematics and physics at the high school and college level since earning his BS in Physics in 2000. In this capacity he has worked at several county colleges and universities in New Jersey. His intention is to become a professor of mathematics education.