$x = 0;
$x += 0.1 for 1..10;
$x_eq_1 = $x == 1 ? 'yes' : 'no';
print("$x = 1? $x_eq_1\n");

##</code><code>##

1 = 1? no

##</code><code>##

...
printf("\$x is really %.16e\n", $x);

##</code><code>##

...
$x is really 9.9999999999999989e-001