Convert from stang to square chain [Gunter, survey]

Unit Definition (stang)
The stang is a traditional Welsh unit of land area generally equal to 3240 square yards, 0.6694 acre, or 0.2709 hectare.

Unit Definition (square chain [Gunter, survey])
The square chain [Gunter, survey] is a traditional unit of area in English surveying, defined to be the area of a square whose side equals Gunter's chain (4 rods or 22 yards). Thus the square chain equals 16 square rods, 484 square yards, 4356 square feet, or exactly 0.1 acre.