1. Tap "Start" to start the game.

2. The formula is displayed in the 9 squares, and the countdown begins.

3. The start button changes to a number (1).

4. Tap a square when the result of the calculation in that square becomes the number.

5. If the answer is correct, the next number (2) will be displayed.

6. Tap the square whose result is 2.

7. Similarly, tap the square whose result is 3, 4, 5, and so on.

8. When all the squares are tapped, the game is over.

9. Tap all the squares in the shortest possible time.