I have posted before about certain materials that seem to attract the other kids even though they are well past their use. Materials like the pink tower, Race to 100 Game, and other things just bring everyone over for "lessons"! In our house, one of those other things is the Knock-Knock Game.
The Knock-Knock game is really a variation on the 3rd step of a 3 period lesson (naming). Using the sandpaper numbers or letters, we turn all of the ones that we are working on upside down, then knock on the back saying, "Knock, knock! Who's there?"
Then we turn it over and say the letter sound or name of the number.
Simple, but always a favorite. Even our little one enjoys knock-knocking and flipping over cards with a big grin just to show us how he knows this game too! I remember when that little girl above used to do the same thing to her older brother.....