Fraction (mathematics)
A
fraction represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certain size there are, for example, one-half, eight-fifths, three-quarters. A
common,
vulgar, or
simple fraction consists of an integer
numerator, displayed above a line, and a non-zero integer
denominator, displayed below that line. Numerators and denominators are also used in fractions that are not
common, including compound fractions, complex fractions, and mixed numerals. The numerator represents a number of equal parts, and the denominator, which cannot be zero, indicates how many of those parts make up a unit or a whole. For example, in the fraction 3/4, the numerator, 3, tells us that the fraction represents 3 equal parts, and the denominator, 4, tells us that 4 parts make up a whole. The picture to the right illustrates or 3/4 of a cake. Fractional numbers can also be written without using explicit numerators or denominators, by using decimals, percent signs, or negative exponents.