Lie on your back and open your legs into a diamond shape (known as Butterfly pose in yoga), with the soles of your feet pressed together and knees out wide. If you have an AbMat, place it under your lower back for support. Extend the arms overhead.
Curl the torso up, and tap the floor in front of your feet. If you can't go all the way up, just do a basic crunch.
Slowly lower back to the starting position to finish off one rep.