What information is needed to calculate the volume of a paperweight?
If you want to determine the volume theoretically, then you will need to know the density and mass of the paperweight. Then you can put those values into the formula:
Or if the paperweight is a perfect cube/rectangle, you can use the formula:
If you wanted to determine the volume experimentally, all you need to do is fill a graduated cylinder with some water, then completely submerge the paperweight in the water. The volume of the paperweight will equal the volume of the water that was displaced. Aka, the difference between of volume of the water with the paperweight in it and the volume of the water without the paperweight in it.