1 pound is about .45359237 kg

13 lb ≈ (13 lb)(.4536 kg/lb) = (13*.4536) kg = 5.897 kg (rounded to 4 significant figures)

13 lb ≈ (13 lb)(.4536 kg/lb) = (13*.4536) kg = 5.897 kg (rounded to 4 significant figures)