Incomplete fractions are often represented like this: 5/?. The question mark indicates that a number or value is missing. An incomplete fraction may be used in simple math problems to represent number as fractions. For example, a teacher might ask students to represent the number 2.15 as a fraction by filling in the incomplete fraction, ?/100. The answer to the incomplete fraction would be 215/100, which is the fraction form of 2.15.
In calculus and other forms of higher math, incomplete fractions may be used to solve rational functions. Specifically, mathematicians use partial fractions to reduce the size of a large fraction with complicated parts and variables. They do this by breaking down a fraction into smaller partial fractions and simplifying these smaller parts before they reconstruct the larger equation. This is particularly useful in problems with multiple variables or equations with different forms of measurement.
In addition to incomplete fractions, there are three basic types of fractions: proper fractions, improper fractions and mixed fractions. Proper fractions refer to fractions in which the numerator, or the top number, is smaller than the denominator, or the bottom number. Improper fractions are the opposite, in which the denominator is equal to or smaller than the numerator. Mixed fractions have whole numbers plus a fraction, such as 3 and 1/2.
Teachers or mathematicians use incomplete fractions in order to express things in a uniform fashion. For example, a teacher might want to compare the number of boys in one school with boys in another school, and so she might ask students to fill in the incomplete fraction, "?/100." Whereas both schools might not have exactly 100 students, this forces students to express the number of boys in each school as a number out of 100, such that the numbers from each school are easier to compare.