An improper fraction is a type of fraction where the numerator (the top number) is greater than or equal to the denominator (the bottom number). For example, in the fraction 7/4, the numerator 7 is larger than the denominator 4. Improper fractions can represent values greater than or equal to 1. Improper fractions can also be converted into mixed numbers, which combine a whole number and a proper fraction. For instance, the improper fraction 9/5 can be expressed as the mixed number 1 4/5, where 1 is the whole number and 4/5 is the proper fraction.