With one more change, the code works fine:

27,28c27,28
<       $s1 =~ /^\d+$/ and $s2 =~ /^\d$/ and
<               &$f(10*$v1 + $v2, $s1 . $s2);
---
>       $s1 =~ /^\d+$/ && $s2 =~ /^\d$/ and
>               &$f($v1 + 10 * $v2, $s1 . $s2);
[download]

and the output I see is

24 = (3 * (14 - 6))
24 = (6 / (1 - (3 / 4)))
24 = ((14 - 6) * 3)
[download]

which seems quite OK.

Now I haven't looked yet if that's an oneliner in some Perl Golf competition, but I'd bet there is something :)

Would be nice to let us now if in the end you had some personal conclusions about your attempted Ruby/Perl comparison.

Thanks,
Krambambuli