Students learn that a proper fraction is a fraction whose numerator is less than or equal to its denominator. For example, 3/7, 16/18, and 4/4 are proper fractions. And an improper fraction is a fraction whose numerator is greater than its denominator. For example, 5/2 and 10/3 are improper fractions. Note that an improper fraction can be rewritten as a mixed number. For example, 5/2 can be rewritten as 2 1/2. Students are asked to write improper fractions as mixed numbers, and mixed numbers as improper fractions.