Position a volunteer so they are sat with their non-dominant arm resting in a comfortable position and their hand is held over the edge of the table with the thumb and forefinger facing up.
Hold the metre stick so the end is level with the top of the thumb and forefinger.
Drop the metre stick - the volunteer should catch it as soon as they can. Record the distance showing just above the finger and thumb.
Repeat the experiment at least 10 times, recording the distance each time.
This is a relatively safe experiment as long as care is taken to ensure that the metre stick falls vertically so that the far end does not approach the volunteers face and eyes.