The 1-of-10 code is a way for people to talk to each other using just their fingers. It works like this: imagine you have ten fingers. Each finger represents a number from 1 to 10. If you want to say the number 5, you hold up your hand with your five fingers outstretched. If you want to say the number 10, you hold up both hands with all ten fingers outstretched.
This code can be used if you can't talk out loud, like if you're trying to be quiet or if you're far away from the person you want to talk to. It's also helpful if you're talking to someone who speaks a different language, because numbers are more universal than words.
Just remember that when using the 1-of-10 code, each finger represents a specific number, and by holding up different numbers of fingers, you can use those numbers to communicate.