MatchPuzzle is an iPad app that can be used by students to practice the four fundamental operations. The rule of the game is very simple: just remove 1 matchstick from the numbers or from the sighs to make the equation true.
The difficulty of the game increases as you play. It starts with simple equations with one term on both sides, but can increase equations with two terms on both sides or 3 terms on one side and one term on the other side. The numbers also become larger as the game progresses.