I am sure you all got 160:
A surveyor's Rod or Pole is 51/2 Yards long
4 Rods linked together = 1 Chain - The length of a cricket wicket or the amount of good hedge you might expect to lay in a day.
10 Chains = 1 Furlong - A unit of measure still used in horse racing
1 Furlong x 1 Rod = 1 Rood or 40 sq Rods - 40 Poles is still the legal maximum size of an Allotment Garden. An average allotment is 10 Poles, or 302.5 sq Yards, or about 250 sq Metres
4 Roods = 1 Acre, or 10 sq Chains, or 160 sq Rods.
Any other links to old units of measure that are still relevant today?