Numenko-in-a-bag features game play and components similar to the Numenko board game - but without a game board and with a few other changes.
The wooden tiles feature digits (0-9), a Multichoice symbol (that stands for the player's choice of addition, subtraction, multiplication, division or "is equal to"), and a Freechoice symbol (that can be a digit or Multichoice). Each player starts with 20 randomly drawn tiles (if playing with 2-4 players; 15 tiles otherwise) and one Freechoice tile. The remaining tiles are mixed face-down on the table.
Playing at the same time, players reveal their tiles and try to create valid equations crossword-style in their own playing area. A Multichoice or Freesymbol tile can be used as a different operator or number in intersecting equations. At any time, a player can return an unwanted tile to the stock in exchange for two newly drawn tiles. If a player uses all of his tiles in one or more equations, then he declares "Done" and draws four new tiles from the stock. Players can rearrange tiles any number of times to incorporate new tiles.
The game ends if a player wants to swap when fewer than two tiles remain in reserve or declares "Done" with fewer than four tiles in reserve. The player who has used all tiles in equations when the game ends wins. If no player fits this description, then players sum their tiles in hand (with a Freechoice tile worth ten points), and the player with the lowest sum wins.