why should we convert units within the metric system?

Question

i need an answer thats it 

Answer 1

I deleted my answer because you said that Tim C. had answered your question.

Answer 2

One reason is to compare things that are in different units. If one thing is in cm and the other is mm it is helpful to convert them to the same unit so you can compare them (to know what is bigger, by how much, etc)

Answer 3

Within the metric system, different slices of a basic unit are indicated by a prefix, example centimeters, kilometers, millimeters. THESE ARE WELL DEFINED, and represent a shifting left or right some number of units.

 

Textbooks have excellent full discussions of this topic, and Googling would also be productive. To repeat that well known material here would be redundant.

 

example: ten MILLImeters = 10 mm = 10 (1 meter•10^-3) = 0.01 m