Simplify the following text for a Grade 5 native English-speaking person.
Original: Braille identified the major failing of the code , which was that the human finger could not encompass the whole symbol without moving , and so could not move rapidly from one symbol to another .
Simplified: Braille saw the biggest problem of the code : The human finger can not feel the whole symbol without moving . This makes it impossible to move rapidly from one symbol to the next .