1. The problem is to understand whether to multiply or add when dealing with a cuboid. 2. A cuboid is a three-dimensional shape with length ($l$), width ($w$), and height ($h$). 3. To find the volume of a cuboid, you multiply its dimensions: $$\text{Volume} = l \times w \times h$$ 4. To find the surface area, you add the areas of all six faces: $$\text{Surface Area} = 2(lw + lh + wh)$$ 5. So, you multiply the dimensions to get volume, and add areas (after multiplying pairs) to get surface area. 6. Therefore, for volume, you multiply; for surface area, you add after multiplying pairs of dimensions.