Silver has a density of 10.5 g/#cm^3#and gold has a density of 19.3 g/#cm^3#. Which would have a greater mass, 5 E\#cm^3# of silver or 5 #cm^3# of gold?
Note that I solved this problem dimensionally. I wanted an answer in grams; after cancelling out the units, I manifestly got an answer in grams. This is a check on whether I divided, multiplied, added correctly. It is all too easy to make an error.