From turning 2 keys simultaneously as in the picture, to see if the arrow points to the number in the box, Bring the two together, plus. The event that the sum is a negative number.
Rotate the two keys simultaneously as shown below. To see the arrow pointing to the number one slot, then put two of them positive. The event has a positive effect as a negative number.
Rotation key 2 keys, at the same time as shown. To see if the arrow pointing to the number in any channel.The number two is positively. The positive is negative with a few.