K, 1, 2
Play one of Arithmetic Invaders: Express addition, subtraction and multiplication games to defend the solar system and master K-2 arithmetic. Also, learn some basic facts about the Solar System. Unlock each level to play it. To do that, complete each mission in the given order. A user is allowed three incorrect hits. The mission length can be chosen: 2, 3 or 5 minutes. Completion of the last mission brings the user the highest rank – DEFENDER OF THE SOLAR SYSTEM.