Which of the following represents the most matter?
3.5 kg
350 g
3.5 x 10³ hg
3.5 x 10⁴ cg

In order to assess these masses, one must convert all the masses to a single a unit so that they can easily be compared...

3.5 kg  =  3.5 kg

350 g   =  0.35 kg

3.5 × 10³ hg = 3500 hg = 350 kg

3.5 x 10⁴ cg  = 35000 cg = 0.35 kg

∴ 3.5 × 10³ hg is the largest mass.

Ido not understand.