# perl -wle 'print 2 ** 128'
       3.40282366920938e+38
       # perl -Mbigint -wle 'print 2 ** 128'
       340282366920938463463374607431768211456

       # perl -wle 'print sqrt(2)'
       1.4142135623731
       # perl -Mbignum -wle 'print sqrt(2)'
       1.41421356237309504880168872420969807857

       # perl -wle 'print 3/7 ** 77'
       2.53847080898319e-65
       # perl -Mbigrat -wle 'print 3/7 ** 77'
       3/118181386580595879976868414312001964434038548836769923458287039207