Math::FixedPrecision provides a way to do decimal math without floating
point errors.

WARNING:  In order for all tests to complete successfully, you must replace
the stock BigFloat.pm with the one located in this distribution.  This file
will also be updated as part of the 5.6.1 distribution, when that is released.
Please copy the included BigFloat.pm to {PERLVERSION}/lib/Math/BigFloat.pm.