Math::BigInt is not very good suited to work with small (read: typical less than
10 digits) numbers, since it has a quite high per-operation overhead and is thus
much slower than normal Perl for operations.

But for some applications, you want fast speed for small numbers without the
risk of overflowing. This is were Math::BigInt::Lite comes into play.

Math::BigInt::Lite objects should behave in every way like Math::BigInt objects,
that is apart from the different label, you should not be able to tell the
difference. Since Math::BigInt::Lite is designed with speed in mind, there are
certain limitations build-in. In praxis, however, you will not feel them,
because everytime something gets to big to pass as Lite (literally), it will
upgrade the objects and operation in question to Math::BigInt.

WWW: http://search.cpan.org/dist/Math-BigInt-Lite/