each use is entitled to a transfer. basically, the card can be swiped/dipped 6 times a day. 3 actual fares, and the 3 metrocard transfers.
If you take a train and a bus in the same trip, you get a transfer, so it only counts as one use. So if you take a bus and a train to and from school, both ways, together, would only be considered 2 uses.
The Thing With The Student Metro Cards Is This3 RidesWith Transfers 6 RidesIf You Live A Certain Amount Away From Your School you Can Ask Your School To Issue A 4 Ride Metro CardWith Transfers 8 Rides
No, you re only entitle to three rides per day. However, the card should include a transfer to subway, very much like the pay per ride (regular) MetroCard.Good luck