My dad was a schoolteacher for many years at a prestigious private boys school. The favourite exercise he would give his class was the word puzzle in the Sydney Morning Herald which is very similar to Chi except it doesn't allow most words ending in an s.
Anyway the kids would comb the dictionaries (not online) and try to find the most words (they just had to be a word whether common or not!).
Then he would ask them to come up with their own 9 letter word and all the possible words to be made from it and that was received with enthusiasm too.
But the number one thing he always said is that if a child reads then they are ahead of the pack and that it makes things so much easier for them later on. Recognising words, spelling, context, grammar, so much is absorbed from the written word. Jigsaw puzzles, eye spy, word games like A-Z on different topics and reading are all engaging activities that stimulate young minds (and older ones too!)
Have you noticed subtitles and news captions with so many misspellings now because it seems some in a generation haven't read widely enough to know the difference between fare and fair or sought and sort etc?
Perhaps I'm just getting old because I'm sounding like my father, but even just today on one of our national morning breakfast programmes called Sunrise they had two major misspellings like those mentioned above - but because I am getting older I can't for the life of me recall exactly what they were!!