This challenge is all about cans or tins - the kind in which you
might buy baked beans or soup.
Is there a best way to stack cans?
What do different supermarkets do? Can you explain
why they might stack cans in that way?
How high can you safely stack the cans?
Investigate the different ways in which cans roll.
Does it make a difference if the can is empty compared with when
it is full? How about a partially-filled can?