Matt,
Have you tried the MathFP package for KVM?
http://home.rochester.rr.com/ohommes/MathFP/ -yu
"MathFP is implemented to provide developers the capability to do calculations involving fractions on
java virtual machines with no support for floats or doubles. For example the KVM (K Virtual Machine) and the CLDC (Connceted Limited Device Configuration) do not support these primitive datatypes."