How to measure the distance with your fingers?

Eye-jumping method: put your hand straight between your eyes and give a thumbs up. Look at the target with the left eye first, then look at things with the right eye, estimate the distance between the object and the target seen by the right eye, and then multiply it by 10 to get the distance between the measurer and the target.

Thumb method (only suitable for people who walk): straighten your right arm, thumb up and point to the target. If the target spans the entire width of the nail in one step, it is about 50 yards (about 45 yards) away from the target. If it is 100 code in two steps, there will be an error if it exceeds 200 codes.