Matchstick description

Math game.
Move 1 matchstick to make correct equal.
Touch on matchstick want to move, then touch on where to place.
If you move false, press "Return", then move again.
If have a very difficult expression, you can abort by pressing "Abort".

Have 2 levels: medium and hard.

keyword: matchstick, math, toán que diêm, syq