A cube has 6 sides
1. a front side
2. a back side
3. a left side
4. a right side
5. a top side
6. a bottom side
Every one of those 6 sides is a 4cm by 4cm square,
and its area is (4cm)×(4cm) = 16cm²
Since there are 6 sides and each one of them has area 16cm²,
The area of them all, which is the surface area of the cube,
is 6 times 16cm² = 96cm²
Edwin