Trying your formulas
While developing your model you are likely to want to check how it works. To do this use Workbooks after you open a project.
To get an introduction to how Evaluating your model works see this tutorial: Evaluating your model
In order to Evaluate your formulas you need a workbook. Workbooks provide a module list that determines the visible formula assets for the evaluation session (scope). The left pane has another list above the modules, the Workbooks section. Each project has an empty workbook to start with.
Click on the plus sign and select Workbook to create a new one or just duplicate an existing workbook. Click the workbook to open a new tab on the right.
After you created a new workbook, you have to choose the required modules to import. To do that click on the square icon on top of the right pane and it will open a dialog where you can select the required modules.
To add formulas simply go ahead and click on the plus sign in the right pane.
Input and output variables
Set which variables you want to input for the calculation session and which ones you want the formulas to calculate (output).
You can reorder formulas if you like by select them (ctrl+click) and use the arrow buttons above.
When you finished editing the values, you can click the Run all button.