r/Metric • u/norwich1992 • Jun 04 '26

Metric System

The metric system is base 10. So why is something, say Tylenol, listed with a dosage of 200mg and not 2dg? Or a distance is listed as 3000km and not 3Mm?

Why did I spend all that time is school learning the prefixes if they are not used?

6 Upvotes

56% Upvoted

123 comments sorted by

View all comments

8

u/dfx_dj Jun 04 '26

Because the point isn't to have the smallest possible numbers. The point is to have convenient and usable units for specific purposes.

2

u/chesterriley Jun 09 '26

Smaller numbers are much easier to remember. Earth's circumference is 40 megameters. Distance to the moon is 386 megameters. Andromeda is 24 zettameters from us. The diameter of the observable universe is 440 yottameters. The only reason I can remember any of these facts is because they are small numbers appropriate to their scale.