What type of decimal cannot be turned into a fraction?

The correct choice refers to a type of decimal known as an irrational decimal. This type of decimal is characterized by its non-terminating, non-repeating nature, meaning it goes on forever without forming a predictable pattern. A common example of such a decimal is the square root of 2 or π (pi).

In contrast, decimals that terminate or have repeating patterns can always be expressed as fractions. For example, a terminating decimal like 2.654 can be written as ( \frac{2654}{1000} ), and a repeating decimal like 0.333... can be expressed as ( \frac{1}{3} ). A decimal that does not consist of a whole number does not inherently preclude it from being represented as a fraction, as demonstrated by examples of decimals such as 0.33, which can also be expressed as ( \frac{33}{100} ).

This understanding reinforces the idea that only those decimals which are both non-terminating and non-repeating cannot be converted to a fraction, as they do not fit into the integer-over-integer structure that defines rational numbers.