What might happen if scientists used different units for the same measurements?

How to convert a density of 0.791g/cm3 to lb/ft3

What substance has a mass of 9.5g and volume of 2.1cm^3

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.