.xx "arithmetic" "provide drill in number facts" .xx "backgammon" "the game" .xx "bcd" "convert to antique media" .xx "ching" "the book of changes and other cookies" .xx "hangman" "guess the word" .xx "maze" "generate a maze problem" .xx "quiz" "test your knowledge" .xx "wump" "the game of hunt-the-wumpus"