How can you create a calculated field in Access?

Creating a calculated field in Access is primarily achieved by defining an expression that calculates values derived from other fields in a table or query. This involves using functions, operators, and references to other fields to perform calculations directly within a query or data entry form.

For example, if you have a table that includes price and quantity fields, you could create a calculated field in a query that multiplies these two fields to generate a total price for each record. This is done by specifying an expression like [Price] * [Quantity].

This method allows for dynamic calculations that are updated based on the values in the related fields, providing a flexible and powerful way to customize the data output within Access.

The other options provided don't pertain to the mechanism of creating calculated fields in Access. Merging tables focuses on combining datasets, writing functions in VBA is useful for procedural programming but does not directly create calculated fields, and importing data deals with bringing information into Access from other sources without calculation involved. Hence, defining an expression to calculate values is the most direct and applicable method for creating a calculated field.