In many Western countries, holding up the index finger signifies "number one" or "first place." However, in some cultures, such as Greece, Russia, and the Middle East, holding up the index finger is considered rude and can be interpreted as an insult or a threat.

In the system used in the Americas, the index finger represents 1; the index and middle fingers represents 2; the index, middle and ring fingers represents 3; the index, middle, ring, and little fingers represents 4; and the four fingers plus the thumb represents 5.

The freely movable part of our hand is made up of five digits (four fingers and one thumb). Each finger has three individual bones, and the thumb only has two. The fingers have three joints each, which can only be bent and stretched in one direction.