C:\>perl -MMath::Decimal64=":all" -le "$x=Math::Decimal64->new('0.085'); $y = Math::Decimal64->new(0.085);$z = NVtoD64(0.085);print $x;print $y; print $z;"

Outputs:
85e-3
8500000000000001e-17
8500000000000001e-17