Constant ounce: a unit of weight. The overall abbreviation is oz.av
1 oz = 28.350g.
1 oz = 16 dram.
16 oz = 1 lb (pound)
Gold is bought and sold in troy ounces.
Troy ounce: A unit of weight. The overall abbreviations are oz.tr (English) and oz.t (USA). Common in the measurement of precious metals such as gold and silver.
1 oz = 31.1035g.
12 oz = 1 lb.
189.12 RMB× 28.35÷31.1035 =172.38 RMB.
Is it reasonable to look at it this way?