unable to square a parameter

[Anonymous]

I set a parameter "clearance" = .1 mm

the following functions don't work:

clearance ^ 2
clearance * clearance

however the following functions do work

clearance * .1
.1 * .1
.1 ^ 2

I have tried this with every named parameter I have and none of them can be squared.  I only want the clearance value stored once so I can't use the working examples.

Any ideas why this won't work?

[jeff_strater · Accepted solution]

units.  The result of clearance * clearance is "mm^2" (a measure of area).  You just need to balance the units by dividing by "1mm" to get "mm" as the units.