Greg Tang has a resume that could get his foot in the door to a lot of places. A graduate of Harvard with both a B.A. and M.A. in economics, Tang has found success as a business executive, a speechwriter, a software designer and owner of a Tae Kwon Do school. After the publication of his first best-selling book for children, "The Grapes of Math" (all of his titles are with Scholastic Press) in 2001, Greg Tang has since been trying the title "unexpected math missionary" on for size. At the heart of his lively math-centered books for children lies his very simple theory that every child can be good at math. Add to that his belief that math should be fun, and an equation that is making sense out of math for kids everywhere is the result.