1. **Problem statement:** Find the surface area of a cube with side length 5 cm. 2. **Formula:** The surface area $A$ of a cube with side length $s$ is given by: $$A = 6s^2$$ This is because a cube has 6 equal square faces. 3. **Calculation:** Substitute $s = 5$ cm into the formula: $$A = 6 \times 5^2$$ 4. **Simplify:** $$A = 6 \times 25$$ 5. **Final answer:** $$A = 150$$ So, the surface area of the cube is 150 cm$^2$.