Bubble wrap is a strange device generally used for packing material. In some areas it is used to great effect as a tension relieving device.
Bubble wrap is a plastic sheet with soft air-filled blisters.
It is impossible to hold this plastic without involuntarily popping one or more of the bubbles. The fact that this can be quite therapeutic was noticed by one Piggy Wilkinson in the last years of the twentieth century. He made a lot of money. Some time before playing the game count the number of intact bubbles on the wrap. If the n pieces really are identical then I suppose you can dispense with this step.