Large sphere's radius = R, small sphere's radius = r, R = 8r surface area of a sphere (SA) = 4×pi×radius^2 So what we need is the SA of the larger in terms of the smaller sphere, so if: SA (of R) = 4×pi×R^2, then plug in "8r" for "R"... SA = 4×pi×(8r)^2 = 4×3.14×64r^2 SA = 12.57×64r^2 = 804 r^2 Therefore the SA of the larger sphere is 804 times the SA of the smaller sphere. I hope that makes sense!
