My Mum sang it to me at night...

Chip Chip my little horse
Chip Chip again Sir
How many miles to Dublin Town
Four score and ten Sir

Chip Chip my little horse
Chip Chip again Sir
will I get ther for candle lighht
Yes, and back again Sir.

However, as 4 score and ten is 90 miles, that seemed a bit long so I wonder id four score shouldnt be three score?