The game consists of 4 difficulty levels. On each level the objective is to fill in missing operations to get the result of given numbers. In addition, there is reward level.
The game ends from one mistake or if you reveal the puzzle.
From version 1.7 the reward scenario appears after solving 10 puzzles on level 1, after solving 9 puzzles on level 2, after solving 8 puzzles on level 3 and after solving 7 puzzles on level 4.
There is also new logical rule: If all the operations are set and "Next puzzle" is pressed, the game ends, if the result is wrong.