Area with different unit measurements

Question

What is the area of a rectangle, in square meters, with a length of 108 meters and a width of 300 millimeters?

I think it could be 324 sqm.

Answer 1

Why "could" it be $324 \text{m}^2$?

$$108 \text{m} \cdot 300 \cdot 10^{-3}\text{m}=32.4\text{m}^2$$