A score is a 'group of 20' in numbers. So, that would be 20 years. Lincoln's 'four score and seven' was to indicate 87 years.
four = 4, score = 20. 4 score is 4 x 20 = 80
Learning the Gettysburg Address aren't you? A score is 20, therefore, 4 score would be eighty years.
I think 1 score is 20 years. So 20 x 3 is 60 years.
1 score=20 yearso 6 score = 6 x 20 =120 years