it's a well known expression because it is a quote from one of Abraham Lincoln's most Famous Speeches.
'Four score and seven years ago...'
Lincoln's Emancipation was proclaimed great honor and contact officicated in glory.
A score is equal to twenty. "Four score and seven years" is eighty-seven years.
One score is 20 years so four score (80) and seven years ago would be 87 years.
a score, as in "Four score and seven years..."
87 A score is 20 years.
A "score" is twenty, so four score and seven = 87.
A score is twenty years. So four score and seven is (4 X 20) + 7 years or 87 years. However, the usual quote is three score and ten years (70 years) which represented the life expectancy in those days.
20
Seven score and fourteen years.
26...a score = twenty (as in "...four score & seven years ago..." means 87 years)
A score is twenty years, so 4 score is 80 years and 'four score and seven' means 87 years.