“Fruits,” of course, means the outcome. What Krishna means is to give up attachment to the results of what you do: that is, to give your best to every undertaking without insisting that the results work out the way you want, or even whether what you do is pleasant or unpleasant.
This is very much what I would like to do with education, what does this look like and how do you make it look positive, even when you renounce the results?
