Think it's 1760 yards in a mile, (drummed in rote fashion daily at school along with our times tables!)
16 oz in a pound
2240 pounds in a ton
4 gills in 1 pint
8 pints in a gallon
1 acre 4840 sq yards
Etc etc etc . . .
Odd how these things stick, yet I can't get my head around metric!