Fraction: A numerical representation of a part of a whole, expressed with a numerator and a denominator. Numerator: The top number in a fraction, representing the number of parts being considered. Denominator: The bottom number in a fraction, representing the total number of equal parts the whole is divided into. Improper fraction: A fraction where the numerator is larger than the denominator. Mixed number: A number consisting of a whole number and a fraction, used to simplify improper fractions that do not divide evenly. Whole number: A number without fractions; an integer.