For an updated list of bugs, see https://rt.cpan.org/Public/Dist/Display.html?Name=bignum The following list is not up to date: Known bugs: * print 2 + 4.5,"\n"; # produces "6.5" but should be actually 65/10 * perl -Mbignum=t -le 'print 2.0' Loading Math::BigInt::Trace MBI import Math::BigInt::Trace :constant upgrade Math::BigFloat::Trace lib Calc Loading Math::BigFloat::Trace MBF import Math::BigFloat::Trace :constant downgrade Math::BigInt::Trace MBI new '2' => '2' (Math::BigInt::Trace) MBF new '2.0' => '2' (Math::BigInt::Trace) 2 The order of MBI and MBF is reversed, since the output is done *after* the new, but the new of MBF downgrades internally to MBI. No solution yet. Please send me test-reports, your experiences with this and your ideas - I love to hear about my work! Tels