Group 1 - The term "Kong Fang Xiong" refers to ancient Chinese coins, which were predominantly round with a square hole in the center, symbolizing a unique physical phenomenon of "outer circle and inner square" [1] - The popularity of the square hole coins began after the unification of currency by Qin Shi Huang in 221 BC, continuing until the late Qing Dynasty in 1900, showcasing a tradition that lasted over two millennia [1] - Various shapes of coins existed historically, including knife-shaped and key-shaped coins, but the round and square design became the standard [1] Group 2 - The choice of the "outer circle and inner square" design was influenced by multiple factors, including casting technology, where coins were cast in molds and then smoothed to ensure uniformity and safety during handling [2] - The round shape of coins minimizes wear and tear, making them easier to carry and less likely to be damaged, while the square hole allows for convenient counting and storage [2] - The design also reflects ancient Chinese cosmology, symbolizing the unity of heaven and earth, with the round shape representing the emperor's authority over the land [3] Group 3 - The round shape signifies flexibility and adaptability, while the square shape represents integrity and principle, aligning with Confucian ideals of "soft on the outside, firm on the inside" [3]