+ can be used on a card that hasn't yet been flipped. it tells you a minimum number for the card. so 9+ could be 9 or vampire (which has a value of 10), 5+ could be any number higher than 5, and 2+ could be any number.
<> is used on a card that has been flipped over, and tells you if the surrounding cards are lower or higher.
the square will select an area of 4 cards, one of which is the vampire card. any cards outside of the area are safe to flip.