Minor Description
"Commons Math" contains formatting classes whose purpose are to beautify the printout of such objects as "complex number" and "matrix" instances.
I suggest that such functionality would be a better fit for "Commons Text".
Rationale is that it is an endeavour unto itself rather than something which other components can easily implement themselves, aside from their "core business".
As an example, in "Commons Math", there was an issue in that fixed precision was maintained in numbers close to 0, leading to meaningless error messages.