The history of Korean mathematics deserves due attention in its own right even though the texts of Korean mathematics were basically written in a canonical Chinese manner. This especially holds true as one adopts a socio-historical approach to researching this subject. Even when only mathematical knowledge is taken into account, an exploration of just how Koreans wrote their mathematical treatises remains significant. This is in part because such treatises were written in Chinese, which ironically was only accessible to those who could read Chinese. When addressing the mechanism of transmission, historians always seem to pose the following question: What happens to mathematical knowledge when it is given a wholly new voice and context? Korean mathematicians like Hong Jeong-Ha 洪正夏 (1684- ?) “translate” Chinese mathematics mainly by employing a Chinese format to compose mathematical texts in Chinese, which demonstrates that ancient Korean text written in Chinese characters may be read in two different ways. This in turn leads to other important questions: How did Korean mathematicians like Hong view Chinese mathematics with their Korean perspectives and in their native context? Also, what can we historians learn from him in treating the transmission issue? In this article, a preliminary study will be conducted of Hong Jeong-Ha and his dialogue with a Chinese astronomer, He Guozhu 何國柱, in Seoul during the early eighteenth century. The dialogue was written by Hong to conclude his treatise on mathematics, the Gu Il Jip 九一集. Therefore, something needs to be said about the treatise in order to explain the dialogue in a Korean mathematical context. Evidently the Gu Il Jip is nothing like a literal “translation” of Chinese mathematical text. However, the manner in which the Korean mathematicians transformed Chinese mathematical knowledge by “partial translation” reveals that mathematics evolved from culture to culture even though the texts were written in the same language, such as Chinese.