#### Answer

Proper fractions have a numerator that is smaller than the denominator (e.g. 1/2), while improper fractions have a numerator that is greater than or equal to the denominator (e.g. 3/2).

#### Work Step by Step

Proper fractions have a numerator that is smaller than the denominator, while improper fractions have a numerator that is greater than or equal to the denominator.
An example of a proper fraction is one-half:
$\displaystyle \frac{1 \leftarrow numerator}{2\leftarrow denominator}$
An example of an improper fraction is three-halves:
$\displaystyle \frac{3 \leftarrow numerator}{2\leftarrow denominator}$
See images for a visual representation.