here is my code

#!/usr/bin/perl -w
use strict;

my $var=10;
my $new_var=testsub($var);
print "$new_var\n";

sub testsub
{

    my $in_arg=shift;
    my $new_arg=$in_arg+10;
    return($new_arg);
}
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Edit: g0n - corrected code tags