20 for about four hundred and fifty years. And after this he gave judges till Samuel the prophet,
21 And after that they asked for a king; and God gave them Saul the son of Kish, a man of the tribe of Benjamin, forty years;
^that's 490, but it does not include Samuel and 50 years between Eli and king Saul.
add 50 years, you get 540, add david and solomon = 584-585?
even if we stick with the 450 + 40 = 490 years.
10 more than 480.