4 

Count along the row, moving your poker chip ( ) over one card for each number as you do so.

Example: If SEVEN is chosen, you count 1-2-3-4-5-6-7 and end up on the King of Clubs.

If you end up on a face-up card, turn all face-up cards face-down (click on each to do so).

If you end up on a face-down card, turn all face-down cards face-up (click on each to do so).

Congratulations! As the name of the trick suggested, you chose the only red card.