mi×ma+h (or Mixmath) is a Canadian board game developed by Wrebbit and published in 1987. It resembles a variant of Scrabble in that tiles are placed on a crossword-style grid, with special premiums such as squares that double or triple the value of a tile and a 50-point bonus for playing all seven tiles on the player's rack in one turn. Unlike Scrabble, Mixmath uses numbered tiles to generate short equations using simple arithmetic. Wrebbit, maker of Puzz-3D jigsaw puzzles, has since been taken over by Hasbro, and it appears that Mixmath has been discontinued.
Gameplay
Mixmath is designed for 2 to 4 players in games lasting roughly 60 minutes. Players should be comfortable with the basic operations of addition, subtraction, multiplication, and division.
Contents
The gameboard is a 14x14 grid. The central four squares are orange and contain the numbers 1 (upper left), 2 (upper right), 3 (lower left), and 4 (lower right)- these squares cannot have tiles played upon them, and are the basis for beginning the game. There are special blue squares scattered throughout the board which contain an arithmetic symbol (a plus, minus, multiplication, or division sign), as well as premium squares labelled as 2x (green) and 3x (red).
There are 108 tiles included with the game, 2 of which are blank and can be used as replacements. Of the 106 playable tiles, there are seven each of the numbers 1 through 10, one 0, one each of the numbers 11 through 20, and one each of every number between 20 and 99 that can be represented as a multiplication of two numbers between 1 and 10 (for example, 21, 24, 25).
There are also four racks that can fit seven tiles, and a pouch from which to draw tiles.
Starting the game
After all the tiles are placed in the pouch, each player draws a single tile. The player with the highest number goes first. Each player places their drawn tile on their rack, and draws six more, for a total of seven.
The first move by the first player must use two of the four initial numbers on the board (1, 2, 3, and 4) to form a simple mathematical equation (such as 1 + 2 = 3, so that the player places a tile numbered "3" to the right of the "1" and "2" squares). Play then continues, as described below. If the first player has no legal moves (such as having only two-digit numbers on the rack), he or she may exchange tiles or pass, and play moves to the left.
Playing tiles
Each played tile is the solution to an arithmetic equation containing two adjacent tiles, such that a line of three numbers is formed. For example, a sequence of an 8 and a 2 on the board may have either a 4 (division), 6 (subtraction), 10 (addition), or 16 (multiplication) played next to it. The position of the played tile may be either to the right or left of the adjacent tiles for a horizontally-oriented equation (representing either 10 = 8 + 2 or 8 + 2 = 10), or either above or below the tiles for a vertical orientation.
Each time a player places a tile, the move is considered final and irreversible. Other players may challenge the move if the tile is not a solution using proper arithmetic. If the player is found to be at fault, he or she must withdraw the tile and end the turn, collecting only the points made from previous moves in that turn.
The player can continue to play tiles on a single turn so long as there are legal moves. Additional plays do not need to use tiles played earlier in the turn, but it may be useful to "build" equations so that difficult high-value tiles can be played. Once a player no longer has legal moves, has played all of the tiles on the rack, or chooses to stop, the turn is finished, the player's score is recorded, and the player draws new tiles from the pouch until the rack has seven tiles again.
Special squares
Sign squares are blue and contain an arithmetic symbol. Any tile placed in that square must be a solution of an equation using that symbol (for example, if the square contains a "+" and an 8 and a 2 beside it, only a 10 may be played in the blue square). Once a tile is placed on that square, the player has the option of immediately drawing a tile from the rack as a bonus. The player cannot "take back" their decision if they discover that the newly drawn tile is not favourable. Premium squares are red and green. When a tile is played on the square, its value is multiplied by the value indicated (either "2×" or "3×").