Dostat výsledek formuláře do Textarea v něm

Chtěl bych výsledek výpoctu hodnot zadaných v inputech, zobrazit v textArea, ale nevim absolutne jak, nevíte jak na to? v TextArea chci aby byl videt výsledek $total.

<?php

declare(strict_types=1);

namespace App\Presenters;

use Nette\Application\UI;

class HomepagePresenter extends UI\Presenter
{
     /** @var Nette\Database\Context */

     private $database;

     public function __construct(\Nette\Database\Context $database)
     {
         $this->database = $database;
     }

    protected function createComponentCalculationForm(): UI\Form
    {
        $supplierList = $this->database->table("suppliers")->fetchPairs("id", "supp_name");
        $form = new UI\Form;
        $form->addSelect('supplier', 'Dodavatel:',$supplierList);
        $form->addText('quantity', 'Ks')
             ->setRequired()
             ->setHtmlType('number');
        $form->addText('price', 'Kč')
             ->setRequired()
             ->setHtmlType('number');
        $form->addSubmit('calculate', 'Spočítat');
        $form->onSuccess[] = [$this, 'calculatePrice'];
        $form->addTextArea('result');
        return $form;
    }
    public function calculatePrice(UI\Form $form, \stdClass $values){
        $values=$form->getValues();
        $price= $values->price;
        $selectedSupp=$values->supplier;
        $quantity=$values->quantity;
        $modifier=$this->database->fetch('SELECT percentage FROM prices WHERE supplier_id = ? AND max >= ? AND min <= ?', $selectedSupp, $quantity, $quantity);
        $total=$price + ($price / 100)* $modifier->percentage;
        return dump($total);

    }

}
?>