Ask students to hold the parachute
Place a large ball near the edge of the parachute.
Try to make the ball roll around the edge of the chute.
As the ball comes towards you, lower the edge you are holding.
When the ball goes past you, raise your edge.
Create a wave by pushing the ball round in front of the edge in a
smooth, steady circle.
Once you've done this try speeding up - or change direction.