Each edge of a cube has length 3 inches. What is the number of square inches in the cube's total surface area?
I know that the total surface area of a cube is the sum of the areas of its six faces. Each face of the cube is a square with side length 3 inches, so the area of each face is 3^2 = 9 square inches. Therefore, the cube's total surface area is 6 times 9, which is 54 square inches.

