Which input validation check ensures numerical data has been entered accurately?

The correct choice is the check digit, which serves as a method of validating that numerical data has been entered accurately. A check digit is a form of redundancy check used for error detection on representations of data. It typically involves performing a calculation on the other digits within a data set to produce a single digit, which is then appended to the data. When the data is entered, the algorithm can recompute the check digit and compare it to the received check digit. If they match, this indicates that the numerical data has been entered correctly.

In contrast, a range check involves verifying whether a number falls within a specified range, ensuring it meets certain numeric constraints, but it does not confirm the accuracy of the data itself. A presence check simply determines if an input has been provided at all, without validating its content or correctness. Lastly, a format check ensures that the data conforms to a particular layout or structure but does not guarantee that the values themselves are accurate or meaningful. Thus, the check digit is the most appropriate choice for ensuring the accuracy of numerical data entry.