Today in math we had a group challenge.  They were given a paper cup and they were told the team that got it to move down the table the most would win.  The challenge was they were not allowed to touch the cup with any objects.  The teams had a planning and testing time.  Then we did a first run.  They learned some strategies from each other and we did a second run.  Then we measured how far the cups went using craft sticks.  I tried to trick them by using different sized craft sticks but they told me right away when you measure you need to use the same sized objects.  So we fixed the problem and found our winner.