In the Standard Units environment, the equality and inequality operators ($=,<,\le ,>,\ge$, and$\ne$) are modified so that they perform the necessary operations on expressions with units.

The properties of the five arithmetic operations are:

where $a$ and $b$ are units; $A$ and $B$ are coefficients; and $r$ is the conversion factor from the unit $b$ to the unit $a$.

To enter a unit in 2-D Math input, select the unit from the appropriate Units palette. If the unit you want is not there, select $\mathrm{unit}$ and then enter the unit.

When you edit a unit, double brackets appear around it.

$\mathrm{with}\left(\mathrm{Units}\left[\mathrm{Standard}\right]\right)\&colon;$

$3\mathrm{Unit}\left('\mathrm{ft}'\right)=\mathrm{Unit}\left('\mathrm{yd}'\right)$

$3=3$

$\mathrm{evalb}\left(\right)$

$\mathrm{true}$

$1.60\mathrm{Unit}\left('m'\right)<\mathrm{Unit}\left('\mathrm{mi}'\right)$

$1.60<\frac{201168}{125}$

$\mathrm{evalb}\left(\right)$

$\mathrm{true}$

$30.48\mathrm{Unit}\left('\mathrm{cm}'\right)=\mathrm{Unit}\left('\mathrm{ft}'\right)$

$30.48=\frac{762}{25}$

$\mathrm{evalb}\left(\right)$

$\mathrm{true}$

$3\mathrm{Unit}\left('\mathrm{ft}'\right)+3\mathrm{Unit}\left('\mathrm{inch}'\right)=\mathrm{Unit}\left('m'\right)$

$\frac{4953}{5000}=1$

$\mathrm{evalb}\left(\right)$

$\mathrm{false}$