The Math of King Mosiah-2

In Mosiah 6:4, we learn that Mosiah takes over for his father at age 30, about 476 years from the time Lehi left Jerusalem.

Twenty-three chapters later, we find out the Mosiah dies at age 63, about 509 years after Lehi left Jerusalem.

Simple math, yes, but these are details that need to be kept in mind for several days, along with dozens of other important details. Also remember that the story of Lehi as we have it was not dictated until after Mosiah was completed.  The Book of Mosiah is complicated.