I love playing games and puzzles with my 4 year old.  When he has trouble on the potty we pull out our portable desk and play a game or puzzle.  I ask him to select and he always chooses Chutes and Ladders.  It took him awhile to get the counting down while he moved the marker but now it is no problem.  He loves the ladders and even the excitement of me (usually) going down the ladder.  I think it is important to teach a 4 year old turn taking, following rules, being a respectful winner etc...  and we practice all of these with this Chutes and Ladders game.  Love it!