This article aims to examine the context surrounding the establishment of sanhak (算學) within the Ministry of Revenue (Hojo 戶曹) during the reign of King Sejo (r. 1455-1468) by reviewing the process of change in the institutional system for mathematics from the Goryeo Dynasty to the Joseon Dynasty. Previous studies have suggested that the ruling class's neglect of miscellaneous knowledge (雜學) and King Sejo's reorganization of the state bureaucracy caused a decline in the level and status of mathematics after its pinnacle during the reign of King Sejong (r. 1418-1450). This article argues that the establishment of sanhak during the 12th year of King Sejo's reign had a multifaceted background that cannot be simply attributed to the neglect of miscellaneous knowledge. Furthermore, it posits that the establishment of the Sanhak Institute marked the birth of a mathematical organization and elevated the status of the “sanwon (算員)” belonging to the organization.