This app is almost like a simple abacus. Each masked face represents a bead in usual abacus. By tapping each mask, it moves toward upper side or lower side. If the mask below the horizontal bar goes up, 1 is added to the number of the counter display. The mask above the bar means 5. You can use this as a calculator.
You can see question number in the lower side of the monitor.
Please try to change the position of the each mask so that the number of the abacus is the same of the question number.
If you complete the number, you can get 1 point.
Please try to get as many points as possible within the limited time.