problem
Seven flipped
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
Can you order the digits from 1-3 to make a number which is divisible by 3 so when the last digit is removed it becomes a 2-figure number divisible by 2, and so on?
How could you arrange at least two dice in a stack so that the total of the visible spots is 18?
These practical challenges are all about making a 'tray' and covering it with paper.