Classifying fractions based on the relative size of their numerators and denominators.
A proper fraction is a fraction where the numerator is less than the denominator, representing a value less than one. An improper fraction has a numerator greater than or equal to its denominator, representing a value greater than or equal to one, and can also be written as a mixed fraction.
Proper: Numerator < Denominator; Improper: Numerator >= Denominator
3/4 is a proper fraction because 3 is less than 4.
7/4 is an improper fraction because 7 is greater than 4, which can also be written as the mixed fraction 1 3/4.