How should I write units? [duplicate]

In a scientific article, should I write "3m", "3 m", "3 meters", or "3 [meters]"?


Solution 1:

This guide at the NIST site is a good place to start.

In particular, you should write "3 m" as in "The bar is 3 m long."

Solution 2:

The abbreviation for meter is m; it is not written between brackets, and you need to add a space between the value and the measuring unit.

The absence of brackets, and the presence of a space to separate the measuring unit from the numeric value is not limited to meter, but it is common for all the measuring units.