This product contains problems that pertain to the common core math standard 5.OA.1 (order of operations) and 5.OA.2 (expressions). It can be used as a center activity and works best in collaborative pairs. This is a great activity to challenge students and to review. Students must answer four problems in a row correctly while also trying to keep the other student from obtaining four in a row, as per traditional tic-tac-toe games. The student only gets to place his X or O if the problem is answered correctly. The kids LOVE this game.