To include units in an expression or to use a redefined Units:-Natural subpackage command in the current Maple session, enter the with(Units:-Natural) command first.

with(Units:-Natural):

3*cm + 2*Unit('m');

$\frac{203}{100}⟦m⟧$

Loading the Units package (which allows you to use the short form to access Units package commands) additionally loads one of the Units subpackages; by default, this is the Units:-Simple package. If you want to use the short form to access Units package commands together with the Natural Units environment, you can do this in at least two ways:

You can load the Units and Units:-Natural packages. This works in either order: if you load the Units package first, it will by default load the Units:-Simple package, but loading the Units:-Natural package overrides this. If you load the Units:-Natural package first, then the Units package detects this when it is loaded and it doesn't load a subpackage.

A variation on this is loading the Units:-Natural package and Units:-CommandsOnly. The latter is a variation of loading the Units package that doesn't load any subpackages.

Alternatively, you can instruct the Units package to load the Units:-Natural subpackage when it is loaded. You can do this with the Units:-UseMode command before loading the Units package:

restart;

Units:-UseMode(natural);

$\mathrm{simple}$

with(Units):

Automatically loading the Units[Natural] subpackage

3*cm + 2*Unit('m');

$\frac{203}{100}⟦m⟧$

The commands redefined in the Natural Units environment to accept input with units are:

To display the help page for a particular command, click the corresponding hyperlink.

For more information on the interaction of these commands, see the Natural Units Example Worksheet.