Question

What is the surface area of the cube? cube with length, width, and height labeled 7 millimeters

Answer 1

One side will be 7x7 because its a square. there are 6 sides so 49x6=
294 mm2

Answer 2

To find the surface area of the whole cube, you need to first find the area of one side.
So one side is just a square with length and width of 7mm. So the area would be 7 x 7 = 49mm². 
Since there are 6 sides on a cube, multiply this area by 6 to give you the whole surface area of the cube.
49 x 6 = 294mm²