如何在數量加上字首，以改寫它們的物理量?

1 kg = 1 000 x 1 g = 1 000 g

1 Mg = 1 000 x 1 000 x 1 g = 1 000 000 g

1 Gg = 1 000 x 1 000 x 1 000 x 1 g = 1 000 000 000 g

1 mg = 1 / 1 000 g = 1E-3 g

1 μg = 1 / (1 000 x 1 000) g = 1E-6 g

1 ng = 1 / (1 000 x 1 000 x 1 000) g = 1E-9 g

所以
456 000 000 g
= 0.456 Gg or 456 Mg

456 Mg (Mg stands for Mega-gram, 1 Mg = 1,000,000 g)