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);

##</code><code>##

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