If you notice, the container is really just two circles, with a diameter of 4 each, and a square with sides of 10.5.
now, if we just get the area of each circle, keeping in mind their radius is half of the diameter, namely r = 2, and get the area of the 10.5x10.5 square, sum them up, that'd be the surface area of the container.
The denominator only changes if you're multiplying/dividing. You may need to create an <em>equivalent fraction</em> to add the fractions together, but you <em>don't</em> add or subtract the denominator.