Scrabble have been sold worldwide and roughly one-third of American and half of British homes have a Scrabble set. There are around 4,000 Scrabble clubs around the world. The game is played by two to four players on a square board with a 15×15 grid of cells (individually known as "squares"), each of which accommodates a single letter tile. In official club and tournament games, play is between two players or, occasionally, between two teams each of which collaborates on a single rack. The board is marked with "premium" squares, which multiply the number of points awarded: eight dark red "triple-word"
Scrabble variants and the equal sign in a Scrabble-like placement. A similar Scrabble-like arithmetic game was published in Australia, during the 1970s, under the name "Equable". Number tiles were white, arithmetic operations and symbol tiles (including decimal point, fraction-dashes, and percentage) were grey, and players could freely take special equal-sign tiles when they made their move. Clearly the name was meant to evoke the conceptual link with Scrabble. The game-board also had bonus-squares. One of the earlier number-based variants, Numble was a physical board game using numbers and basic mathematic equations (addition, subtraction, multiplication, division). Players form valid equations. Triolet uses pairs