mixed fraction
A fraction expressed as an integer and a proper fraction, e.g. 1½. Used in mathematics.
Please teach me how to convert a mixed fraction to an improper fraction.
compound number
A number expressed in multiple units, such as feet and inches. Rarely used outside specific contexts.
Outside mathematics, 混分数 can also be used to mean a compound number.
真分数 is a proper fraction (numerator < denominator), which is the fractional part of a 混分数.
Compound of 混 (mixed) + 分数 (fraction). The term is a straightforward technical coinage.