The property that is demonstrated is the communative property, i think.
8 7/8+(7 5/6) - 2 1/3)
71/8 +(47/6 - 7/3)
71/8+ 11/2
115/8
We know that there are 11 sections that could be filled, one of which is.
So, one out of 11 of the sections is shaded... Now, all you would need to do is create a fraction to demonstrate that.

of the figure is shaded.
I hope this helps!
X=6 because 6 x 6 x 6 = 216
6/10 is the closest to zero because if you simplify all the fractions you can, then convert them into decimals, you can easily find what is closer to zero:
8/12 = 2/3 = 0.66
5/8 = 0.62
6/10 = 3/5 = 0.60
2/3 = 0.66
0.60 or 6/10 is the smaller number ;))