Which of the following is not a type of decimal?

Decimals are a way of expressing fractions or divisions in a base ten system, and they can be categorized into different types based on their structure. A terminating decimal is one that comes to an end after a certain number of digits (e.g., 0.75), whereas a repeating decimal has one or more digits that repeat indefinitely (e.g., 0.333…). A non-terminating decimal, on the other hand, continues indefinitely without repeating a pattern, such as the decimal representation of π (3.14159...).

An integer, such as 5 or -2, is a whole number and does not have a decimal representation unless it is converted into a decimal form (e.g., 5 becomes 5.0). However, integers themselves are not classified as decimals. This is why the choice identifying an integer as not being a type of decimal is correct. In contrast, the other four options presented all relate directly to specific classifications of decimal numbers.