If someone says to you: "give me five", do not search your pocket to get five yuan! It will make others laugh! The person's not asking for your money, but your fingers.
In the US, "give me five" or "give me the high five" is a popular gesture (动作). You can see it often in films or on TV. It means the clapping (拍) of each other's raised right hands together.
People do it when they meet for the first time or something happy happens. For example, a student has good marks in exams or wins a lottery ticket (彩票).If a football team wins a game, the players will give high fives to everyone around to celebrate.
This gesture may come from the old Roman gesture of raising the right arm for the emperor to show respect. This also showed that the person raising his arm did not have a sword (刀) in his hand.
Why not try to give the high five to your friends?