Sometimes the tank amount or gallons used or spray rate isn't relevant, or might not be known. In those cases, simply select Units and enter the number of treated acres. Your total product used will calculate correctly.
The first step is to change the recording information to units if it is not already selected. When units is selected then N/A will show up in the per 100 and per tank columns, since these are not used in dry or unit applications.
The next step is to enter the number of treated acres. That's it!