One score is a unit of measurement equal to 20 units. The origin of the word is believed to be derived from the Old Norse word "skor," meaning to notch or scratch.
The early use of the word refers back to a time when scratches, or marks, were made when counting large quantities of items. The person counting would notch a stick or board for each unit of 20 to facilitate adding final sums. The same tally system was later used in pubs to keep track of tabs for customers.
The term "score" can be used as a suffix with another whole number to mark a multiple of 20. The expression "threescore years" was used several times in the King James translation of the Bible in connection with character ages of 60 years or more. Shakespeare uses the words "threescore and ten" to indicate 70 years in "Macbeth."
Two prominent individuals in United States history used the term "score" to represent the number 20 in their speeches. The term "four score and seven years" was used in the opening line of the Gettysburg Address by Abraham Lincoln to indicate 87 years. Dr. Martin Luther King, Jr. used the phrase "five score years ago" to indicate100 years in his "I Have a Dream" speech.