text: 1 g/cm is equivalent to:
  : = 1000 g/L (exactly)
  : = 1000 kg/m (exactly)
  : ≈  (approximately)
  : ≈  (approximately)
  1 kg/m = 0.001 g/cm(exactly)
  1 lb/cu ft ≈  (approximately)
  1 oz/US gal ≈  (approximately)