We know that the scale is 2 cm = 8 m.
To write it as a ratio, we have to have the same units for the model and the real world.
Then, if we apply the units conversions we get:
![\frac{2\operatorname{cm}}{8m}\cdot\frac{1m}{100\operatorname{cm}}=(2)/(800)=(1)/(400)=1\colon400]()
The scale is 1:400, meaning that one unit in the drawing represents 400 units in the real world.
Answer: 1:400