5. Click on the + to create a calculated field, in the bottom of the View Fields List panel.
6. Set the Calculated Field Name to Cost Note: the name for this field can be anything, it will not change the way the union works if it's called something else.
7. Click on the ∑ button.
x. Select the Camp Cost field from the -Select Field-drop down, and click + Add.
x. Close the bracket by clicking ).
x. Click the * button to multiply the field by a value.
x. Type -1 into the text entry field, and click + Add to put in your calculation.
8. Click the Validate button to ensure your calculation is built correctly.
9. Click the Save button to complete your calculation.