9 sq. ft. = 1 sq. yd. .0001 sq. centimetre
30-1/4 sq. yds. = 1 sq. rod .01 sq. decimetre
160 sq. rods } 1. sq. metre
4840 sq. yds. } = 1 acre 100. are
640 acres = 1 sq. mile 10,000. hectare
1,000,000. sq. kilometre
In measures of volumes we are as badly off: