use warnings;

my $x = 1.4142135623730951;
my $y = 1.4142135623730952;
my $z = 1.4142135623730953;

print "$x $y $z\n";

$x == $y ? print "x and y are numerically equal\n"
         : print "x and y are numerically unequal\n";

"$x" eq "$y" ? print "x and y are stringwise equal\n"
             : print "x and y are stringwise unequal\n";

$z == $y ? print "z and y are numerically equal\n"
         : print "z and y are numerically unequal\n";

"$z" eq "$y" ? print "z and y are stringwise equal\n"
             : print "z and y are stringwise unequal\n";

__END__

Outputs:

1.4142135623731 1.4142135623731 1.4142135623731
x and y are numerically equal
x and y are stringwise equal
z and y are numerically unequal
z and y are stringwise equal