How much roods in an acre?
There are four roods in an acre, according to The Oxford English Dictionary (OED) online, which gives among its definitions of "rood":
"7. a. A unit of land area equal to 40 square rods (a quarter of an acre, approx. 0.1012 hectare), but varying locally. Also: †a plot of land of this size (obs.). Cf. rod n.1 8b. Now chiefly hist."
The Oxford English Dictionary can be accessed online free of charge through the websites of many public libraries and universities. For more information, please consider visiting your local library or using its online services. Your question was answered by a student Librarian in training.