Common Denominator Tic-Tac-Toe! Just like regular Tic-Tac-Toe, the object of the game is to connect 3 in a row with your X or your O! But for each square you want to place your X or O in, you must first find the common denominator for the pair of fractions in the box, and rewrite each fraction using that common denominator. Then, check your answer with the matching QR code. If you’re right, you can claim the box with your X or O. If you’re wrong, you lose your turn! Have fun! QR Answer Codes