This calculator requires the use of Javascript enabled and capable browsers. To begin play, click on one of the blocks on the game board. Each block has a number value of 3, 2 1 or 0. Each click will decrement that block's value by 1. It will also reduce the values of the 4 surrounding blocks at positions North, South, East and West. The objective is to countdown all of the blocks to zero. Keep in mind that if a block is already at zero and it is decremented, it will reset to the value of 3. There are 9 different difficulty ratings. We suggest that you initially set your rating to the easiest level, 1, to get the idea of the game. 9 is the most difficult rating and is very intense. Enjoy.