Convert the following masses into kilograms: a) 58475 μg b) 406 dg c) 1900 cg d) 65 Mg e) 945 Dg

$$0.058475\, \text{g} \times \frac{1\, \text{kg}}{1\,000\, \text{g}} = 0.000058475\, \text{kg}$$

The mass is $\boxed{\text{0.000058475 kg}}$.

$$40.6\, \text{g} \times \frac{1\, \text{kg}}{1\,000\, \text{g}} = 0.0406\, \text{kg}$$

The mass is $\boxed{\text{0.0406 kg}}$.

$$19\, \text{g} \times \frac{1\, \text{kg}}{1\,000\, \text{g}} = 0.019\, \text{kg}$$

The mass is $\boxed{\text{0.019 kg}}$.

(Note: $1\, \text{Mg} = 1\,000\, \text{kg}$)

$$65\, \text{Mg} \times \frac{1\,000\, \text{kg}}{1\, \text{Mg}} = 65\,000\, \text{kg}$$

The mass is $\boxed{\text{65000 kg}}$.

$$9\,450\, \text{g} \times \frac{1\, \text{kg}}{1\,000\, \text{g}} = 9.45\, \text{kg}$$

The mass is $\boxed{\text{9.45 kg}}$.

$$1.854\, \text{g} \times \frac{1\, \text{kg}}{1\,000\, \text{g}} = 0.001854\, \text{kg}$$

The mass is $\boxed{\text{0.001854 kg}}$.

(Note: $1\, \text{tonne} = 1\,000\, \text{kg}$)

$$23\, \text{tonnes} \times \frac{1\,000\, \text{kg}}{1\, \text{tonne}} = 23\,000\, \text{kg}$$

The mass is $\boxed{\text{23000 kg}}$.

$$12\,500\, \text{g} \times \frac{1\, \text{kg}}{1\,000\, \text{g}} = 12.5\, \text{kg}$$

The mass is $\boxed{\text{12.5 kg}}$.

$$40\,500\, \text{g} \times \frac{1\, \text{kg}}{1\,000\, \text{g}} = 40.5\, \text{kg}$$

The mass is $\boxed{\text{40.5 kg}}$.