From "Xiao Li and the Chinese teacher are different in age and Xiao Liu lives in the same community", we can know that Xiao Li and Xiao Liu are not Chinese teachers, that is to say, Xiao Wang is a Chinese teacher. From "Xiao Liu lives in a community with a Chinese teacher, and Xiao Liu and a math teacher often play chess", we can know that Grandpa Xiao Liu is not a math teacher, that is to say, Xiao Liu is an English teacher, so Xiao Li is a math teacher.