Summarize this article in one sentence.
All sheet music uses the same universal numbering for the fingers and thumb on each hand. If you memorize the number for each finger, you'll be able to read finger positioning notations. The numbering starts with your thumb at number 1 and goes to your pinky finger at number 5. The left hand is a mirror image of the right hand, using the same numbers for the same fingers.

Summary:
Number your fingers.