Building a tower from clear plastic water cups, found in Scouting Magazine Dec 12 /Jan 13
loads of Disposable plastic cups
Lots of sheets of A5 Card
1 full 330ml can of soft drink (or similar)
1) Put 3 cups upside down in triangle (see attached)
2) lay card on top
3) Place can on top for 10 seconds and see if it holds
4) if structure holds repeat adding layers, see which team can go the highest.