What is the term for obtaining an approximate value?

The term that refers to obtaining an approximate value is "estimate." An estimate is a rough calculation or judgment about the value, number, quantity, or extent of something. It is often used when exact data is unavailable or when a quick assessment is needed, allowing for a practical approach to problem-solving or decision-making.

In scientific contexts, estimates are useful because they provide an approximate understanding of parameters, which can then be refined with further data or analysis. In contrast, terms like "calculate," "assess," and "evaluate" imply a more precise and often more detailed process. To calculate means to determine a numerical result through computation, while to assess is to evaluate critically, often involving comparisons or measurements against standards. Evaluating is generally a broader process that encompasses critical thinking or judgment regarding the significance or quality of something. Thus, "estimate" specifically denotes the approximation aspect effectively.