Final answer:
A text box that displays a calculation is known as a computed or calculated control, used in various software applications.
Step-by-step explanation:
A text box that displays a calculation is an example of a computed or calculated control. This type of control is commonly used in forms in various software applications, including database management systems (DBMS), spreadsheets, and custom business applications.
It automatically calculates a value based on other data entered into the form or based on predefined criteria and then displays that value in a text box or similar display area. Calculated controls save time and reduce errors by eliminating the need for manual calculations.
On a spreadsheet, for example, a calculated control could be a cell that uses a formula to sum values from other cells. In a database application, it might display the result of a query or an aggregate function like SUM or AVERAGE.