forty: Num 1:41, Num 26:47, Reyher, who is followed by Scheuchzer, assigns the following space to the soldiers of each of the tribes, whilst remaining close to each other in their ranks, allowing one square cubit to each; but if we take in the arrangement, not only the soldiers, but the tents, the families, etc., a much larger extent of ground is requisite:
Tribes Breadth - in cubits Length - in cubits Totals - sq.cubits