I think it's some American thing that said 4 score and whatever years ago. Because it was used in the same sentence as whatever years, the score refers to an amount of years. Score on its own means 20, but it does not have units attached.
standard deviations
1 score = 20 years 1 score = 20 years
You can't convert that. You can only convert units that measure the same type of thing - for example, units of length to units of length, units of mass to units of mass, units of time to units of time, etc.
It doesn't make sense to convert that. You can only convert units of the same kind, e.g., units of length to units of length; units of area to units of area; units of time to units of time, etc.
120
20 units. NB 12 units = 1 dozen 13 units = Baker's dozen 20 units - 1 score 144 units = 1 gross.
Why is the earth divided into very long units of time
A score is equal to 20 units, so 5 scores would be 100 units in total.
A score is 20.
Twenty
64 units of time!
You can't convert between units of mass and units of time.
A score is 20, so 4 score is 80.
One score is 20 units (could be hours, days or years), thus threescore years is 60 years.
eras.
standard deviations
As a score is 20 units (usually years), Seven tenths of twenty would be fourteen.