Read and write the mass on each of the scales in: a) grams b) kilograms.

Each major division (e.g., from 0 g to 200 g) is divided into 5 smaller segments by 4 minor marks.
Therefore, the value of each minor division is $\frac{200 \text{ g}}{5} = 40 \text{ g}$.

The pointer on Scale A is at the 900 g mark.

a) Mass in grams: $900 \text{ g}$

b) Mass in kilograms:

Mass on Scale A: a) $\boxed{\text{900 g}}$, b) $\boxed{\text{0.9 kg}}$

The pointer on Scale B is two minor divisions past 400 g.

a) Mass in grams: $400 \text{ g} + (2 \times 40 \text{ g}) = 400 \text{ g} + 80 \text{ g} = 480 \text{ g}$

b) Mass in kilograms:

Mass on Scale B: a) $\boxed{\text{480 g}}$, b) $\boxed{\text{0.48 kg}}$

The pointer on Scale C is three minor divisions past 1 kg (which is 1000 g).

a) Mass in grams: $1000 \text{ g} + (3 \times 40 \text{ g}) = 1000 \text{ g} + 120 \text{ g} = 1120 \text{ g}$

b) Mass in kilograms:

Mass on Scale C: a) $\boxed{\text{1120 g}}$, b) $\boxed{\text{1.12 kg}}$