The Dangojeon refers to the 5 mun denomination of the Sangpyeong Tongbo (常平通寶) Korean cash coins introduced in February 1883 following the disastrous introduction of the earlier Dangbaekjeon (當百錢) two decades earlier. The Dangojeon had a nominal value that was five times higher than that of the regular yeopjeon, but its purchasing power was just twice as high, like the previous series of high denomination Sangpyeong Tongbo cash coins, this would prove to be a major cause of inflation and disrupted the Korean economy.

The mun was introduced as the main currency of Korea in 1625 and stayed in use until 1892. Prior to the mun, cash coins with the inscriptions tongbo (通寶) and jungbo (重寶) and silver vases called ŭnbyŏng were used as currency in the Goryeo Dynasty (918–1392), as well as imported Chinese currency. The mun resembled and was derived from the Chinese wén. Coins denominated in mun were cast in copper-alloys such as brass or bronze and were round with square holes. From the 17th century until the end of the 19th century, coins denominated in mun bearing the inscription Sangpyeong Tongbo, introduced in 1633, were the most widely circulated currency. In 1888, coins were struck in small numbers denominated in mun and won. The mun was replaced in 1892 when the yang was introduced.