Calculator's revenge

Calculator's revenge is a minimalist puzzle game based on simple arithmetic.

How to play:
Drag the tiles to form or modify operations on the board.
Tap on the operations, and they will be replaced with the result. It will be added to the current score. If the board is filled with tiles and there are no operations available, the game ends.

Tips:
Aim for big results, using addition and multiplication.
Avoid negative results: they will add extra «minus» tiles.
Optimize your moves: with each move may appear new tiles.