Convert from rotl, rotel, rottle, ratel [Arab] to dan [China]

Unit Definition (rotl, rotel, rottle, ratel [Arab])
The rotl, rotel, rottle, ratel is a traditional Arab unit of weight corresponding to the Roman libra, the French livre, and the English pound. There was considerable variation in the unit from time to time and from place to place, but usually the rotl was about 0.9-1.15 pound (450-530 grams). However, in some areas of the Near East, such as Syria and Palestine, larger rotls of 5.5 to 6 pounds (2.5-2.8 kilograms) were used. This unit has many spellings in European languages.

Unit Definition (dan [China])
The dan [China] is a traditional Chinese weight unit, previously spelled tan in many English works. During the European colonial era the unit was equal to 100 catties or 133.333 pounds. In modern China the dan is equal to 100 jin, which is exactly 50 kilograms (110.231 pounds). The dan is the Chinese equivalent of the European quintal or hundredweight.