Why do we need to know the metric system?

Upon further investigation, after asking on the discussion boards, another student told me the blog assignment for this week was basically explaining to children why we need to know the metric system. I would tell them it's the system of measurement used by the rest of the world, and in order to translate measurement with any other country, you need to be familiar with the metric system. I would also explain that because it is a base ten system, it is easier to calculate and convert from one form of measurement to the next.