In the Natural Units environment, the arithmetic operators (+, -, *, /, and ^) are modified so that they perform the necessary operations on expressions with units.

Given units $x$ and $y$, the properties of the five arithmetic operators are:

where $r$ is a rational number; $z$ is an appropriate unit from the given system; and $\mathrm{za}$, $\mathrm{zb}$, and $\mathrm{z0}$ are appropriate multipliers.

$\mathrm{with}\left(\mathrm{Units}\left[\mathrm{Natural}\right]\right)\:$

$3m+7\mathrm{ft}$

$\frac{6417}{1250}⟦m⟧$

$\frac{3\mathrm{cm}}{s^2}7g$

$\frac{21}{100000}⟦N⟧$

$-32m$

$-32⟦m⟧$

$\frac{1}{32S}$

$\frac{1}{32}⟦\mathrm{\Omega }⟧$

${\left(3m\right)}^2$

$9⟦m^2⟧$

$4^x$

$4^x$