Which of the following is the term for a number that cannot be expressed as a fraction?

The term for a number that cannot be expressed as a fraction is "irrational." Irrational numbers are those that cannot be represented as the quotient of two integers, meaning they cannot be written in the form a/b where a and b are integers and b is not zero. This includes numbers such as the square root of 2 or pi, which go on forever without repeating in decimal form.

In contrast, integers are whole numbers that can be positive, negative, or zero but can always be expressed as fractions (for example, the integer 3 can be written as 3/1). Rational numbers include all fractions that can be expressed as the ratio of two integers, while whole numbers are non-negative integers, which also fit within the rational category. Therefore, the choice of "irrational" accurately identifies the correct classification of numbers that do not conform to fractional representation.