Great question, in the old days you could basically eliminate those jobs and extend the other jobs
In this case the most positive thing that you can do in those short term jobs is emphasize things that you achieved (ie targets hit, changes you made and the effects of the change, ie I pushed though an initiative that saved x dollars or increased sales x amount) that way even if you were there for a short period of time you made a impact there, and then moving on makes some sense.