There are 10 concrete block per m2.
90 * 140 acres = 50,990 390.9 m2
20.66 blocks per m2 when laid flat (block size 100 x 440 x 215)
140 m2
13 m2
50
10000 cm2 in one m2
1 cent = 40468 m2
complete: 1300cm2=------M2
5000 m2 is 1.24 acres.
There are about 46.15 acres in 186,764 m2
1000 m2 = 0.247 acres