This teaching resource, compatible with iPad, Android and IWB is another puzzle for encouraging children to work on their problem solving skills. It is a variation on the traditional 15 Puzzle. Slide the tiles around until they run in alphabetical order from the top left.. Solving it in any number of moves is one challenge but aiming for perfection and completing it in the minimum possible 23 moves should prove even more so.
The resource should run on any modern browser on any device and so could make a useful homework challenge that most children will be able to access on whatever they have at home.
Go to puzzle.
A similar resource, but requiring some mathematical reasoning is here.