In 100 Floors: level 82 you will see a wooden door and a spinning clock on the right door. You will also see a painting of what looks like a dragon or a tail of the dragon. You can spin the clock on the right door by tapping on it. The green spinner will then spin in a clockwise direction.
Hidden on the bottom of the floor to the right is the missing piece to your puzzle on the left door. Tap on it to reveal the piece on the ground then pick up the other spinner. Place the spinner on the left door then spin the right one exactly 7 times then tap the one on the left exactly 2 times to reveal the last missing piece of the puzzle. Tap the last piece then place it on the floor on the far right then hold the leaver down then proceed to floors level 83.