Součet více proměnných

$today_paid_czk = $this->modelsManager->executeQuery("SELECT sum(total) as total_paid_czk FROM Orders WHERE DATE(date_created) = CURDATE() AND status = 'paid' AND currency = 'czk'")->getFirst();
        $this->view->setVar('today_paid_czk', $today_paid_czk['total_paid_czk']);
$mobile_today_paid_czk = $this->modelsManager->executeQuery("SELECT round(sum((total)*0.53),0) as mobile_total_paid_czk FROM Orders WHERE DATE(date_created) = CURDATE() AND status = 'paid' AND user_agent LIKE '%Mobilní%' AND currency = 'czk'")->getFirst();
        $this->view->setVar('mobile_today_paid_czk', $mobile_today_paid_czk['mobile_total_paid_czk']);        

 $celkem_today_czk =  $today_paid_czk  + $mobile_today_paid_czk;
      $this->view->setVar('celkem_today_czk', $celkem_today_czk);