First find the area of one side.
The area of the side of a cube is s^2 where s is the length if one edge.
The edge length is given as 2/3, so the area of a side is 2/3^2 which is equal to 2/3 x 2/3 = 4/9 square units.
A cube has 6 sides so now to find the surface area of the cube multiply the area of one side by 6 sides:
4/9 square units x 6 = (4 x6)/9 = 24/9 which can be rewritten as 2 2/3 square units
The answer is 2 2/3 units^2