Click on the flashcard to begin the game. Add or subtract to solve the problem shown. Type in your answer, then press enter to see the next problem. Race against the clock and try to solve as many problems as you can in 2 minutes! The game will automatically stop at the end of 2 minutes. Note: games require more memory and a newer browser. If game does not load, try updating your browser to the latest version. This game takes a few seconds to load.