Foreigners often make some strange mistakes in Chinese when they study the most difficult language--- ---Chinese. We try to analyze typical sentences to correct these errors.

          Zhèshì èr fēn zhī sān.
False: 这是二分之三。
          Zhèshì sān fēn zhī èr.
True: 这是三分之二。

二分之三(two-thirds)is derived from the English way of showing fractions. In English, the numerator is a cardinal number whereas the denominatior is an ordinal number which may appear in the plural form. In Chinese, the denominatior always comes before the numerator. Thus it should be 三分之二.