You could just use a calculator. I got 12.
Or use difference of squares since it is in the form a^2 - b^2 = (a+b)(a-b)
So it would look like:
(666 + 1/222 + 666 - 1/222)(666 + 1/222 - 666 + 1/222) =
(2*666)*(2*1/222) =
(2*2*666/222) = 2*2*3 = 12
Ta-dah!