so my kid told me about this game that i think is so cool. what you do is you try to create numbers by using exactly four 4's. for example:
1 = (4+4)/(4+4)
2 = (4*4)/(4+4)
3 = 4 - (4^(4-4))
So you can use + - * / ^ square root and these things 4! and 4 with the sideways M.
it's pretty fun and challenging the further you go!