Product Game

Play begins with each player covering a factor from 1 to 9 at the bottom. The 2nd player then covers the product of those two numbers on the game board. The 1st player can then move either the X or O and covers the new product. Play continues until a player can cover four products in a row, horizontally, vertically or diagonally. Player who lost gets to choose to go first or second the next game. First appearance of this game that I know is the Middle Grades Mathematics Project, then the Connected Mathematics Project. Available to play vs the computer at NCTM's Illuminations,