Defining values — the := assignment

The one move you will make most: name := value. The name on the left becomes a variable you can reuse anywhere below; the result shows to the right. Type := as a colon followed by an equals sign — the editor renders it as the assignment arrow.

Now change price_each to 9 and watch subtotal update on its own. Every cell that depends on a value re-evaluates the moment you edit it — a NapkinCalc sheet is a spreadsheet without the grid of boxes.