Simplify the following text for a Grade 9 native English-speaking person.
Original: Hanna and Barbera ultimately wrote and directed one hundred and fourteen Tom and Jerry cartoons at the MGM cartoon studio in Hollywood , California between 1940 and 1957 , when the animation unit was closed .
Simplified: One hundred and fourteen Tom and Jerry cartoons were produced by the MGM cartoon studio in Hollywood from 1940 until 1957 .