A cuboid measures 5 centimetres long, 3 centimetres wide and 2 centimetres high. Enter the number of cubic centimetres in its volume.

Explication

Volume counts the unit cubes packed inside, and this box holds 5 by 3 of them in each layer with 2 layers stacked up. Adding the three measurements instead gives 10 and describes no space at all, because a space needs three lengths multiplied together rather than summed.