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

Note: Prior to Maple 2015, units were displayed surrounded by double brackets.

with(Units[Standard]):

3*Unit('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 Standard Units environment, you can do this in at least two ways:

You can load the Units and Units[Standard] 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[Standard] package overrides this. If you load the Units[Standard] 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[Standard] 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[Standard] subpackage when it is loaded. You can do this with the Units[UseMode] command before loading the Units package:

restart;

Units[UseMode](standard);

$\mathrm{simple}$

with(Units):

Automatically loading the Units[Standard] subpackage

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

$\frac{203}{100}⟦m⟧$

The commands redefined in the Standard 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 Standard Units Example Worksheet.