Convert from cuerda to morgen [South Africa]

Unit Definition (cuerda)
The Cuerda is a traditional unit of land area in Puerto Rico. The cuerda is equal to about 3930 square meters, 4700 square yards, 0.393 hectare, or 0.971 acre. Because the cuerda and the acre are so close to being equal, they are often treated informally as being equal. Mainlanders sometimes call the unit the "Spanish acre."

Unit Definition (morgen [South Africa])
The morgen is a traditional unit of land area in Northern Europe. "Morgen" means "morning," and most likely the unit arose as the area a yoke of oxen could plow in one morning. The Dutch morgen, also used in Dutch colonies including old New York, equals about 2.10 acres or 0.850 hectare. In South Africa, this unit was defined to equal 10 246 square yards, which is 2.1169 acres or 0.8567 hectare. In Scandinavia and northern Germany, the morgen is a smaller unit equal to about 0.63 acre or 0.25 hectare (2500 square meters). The Prussian morgen, standardized at 2553.22 square meters, was in common use during the nineteenth century. In Austria and southern Germany, the morgen was often the same as a joch, typically defined to be 0.5755 hectare or about 1.422 acres.