You missed a few intermediate units, which might help somewhat to explain it:
Derived from surveyors’ tools, a chain is 22 yards. (It is also 4 rods, making a rod equal to 5½ yards; go figure.) Ten chains make a furlong, and there are 8 furlongs to a mile. So there you are. Incidentally, an acre is 1 furlong × 1 chain. It may be madness, yet there’s system in ‘t.
Derived from surveyors’ tools, a chain is 22 yards. (It is also 4 rods, making a rod equal to 5½ yards; go figure.) Ten chains make a furlong, and there are 8 furlongs to a mile. So there you are. Incidentally, an acre is 1 furlong × 1 chain. It may be madness, yet there’s system in ‘t.