Simply click on the link provided before at
http://www.rasmussenreports.com/publ..._tracking_poll and read Rasmussen's own description of the poll. Specifically it states:
"The Rasmussen Reports daily Presidential Tracking Poll for Monday shows that 33% of the nation's voters now
Strongly Approve of the way that Barack Obama is performing his role as President. Thirty-four percent (34%)
Strongly Disapprove giving Obama a Presidential Approval Index rating of -1." [emphasis added]
I assumed that everyone knew that was how Rasmussen did his index since he states it in every poll. To see his full results, which show a 54% approval rating, go to
http://www.rasmussenreports.com/publ..._index_history. Note that Rasmussen consistently shows a lower approval rating than other major polls by 3-5% which is presumably associated with methodological differences.