<?php defined('SYSPATH') OR die('No direct access allowed.');

class Docx extends Base_Docx { }

<?php defined('SYSPATH') OR die('No direct access allowed.');

 abstract class Base_Docx {
    
    public $a;
    public $b;
    
    public static function summ(){
        return $a + $b;
    }
}

$docx = new Docx();
                $docx->a = 5;
                $docx->b = 2;
                
                $this->template->footer = $docx->summ;

<?php defined('SYSPATH') OR die('No direct access allowed.');

 abstract class Base_Docx {
    
    public $a;
    public $b;
    
    public function summ(){
        return $this->a + $this->b;
    }
}

<?php defined('SYSPATH') OR die('No direct access allowed.');

class Controller_Docx extends Controller_Template{
    
    public static function before() {
        parent::before();
        $this->template = View::factory('testModule');
    }

    public function action_index(){
        /*$this->a = $_POST['a'];
        $this->b = $_POST['b'];*/
        
        $this->template->summ = '$summ';
    }
} 

<?php defined('SYSPATH') OR die('No direct access allowed.');

class Docx extends Base_Docx { }

<h3>Страница проверки работы модуля KohanaDocx</h3>
<p><?=$summ?></p>

<?php defined('SYSPATH') or die('No direct script access.');

Route::set('docx', '<docx>(/<action>)')
   ->defaults(array(
      'controller' => 'docx',
      'action'     => 'index',
   ));