<?php

$num1 = $_GET['number1'];
$num2 = $_GET['number2'];
$result = 0;
$answer = $_GET['vastus'];

switch($_GET['tegevus'])
{
    case 'korruta':
    $result = $num1 * $num2;
    break;

    case 'liida':
    $result = $num1 + $num2;
    break;

    case 'lahuta':
    $result = $num1 - $num2;
}

if($result != $answer)
{
    echo 'Vale vastus!';
}
else
{
    echo 'Õige vastus';
}

?>

<form method="GET">
<table>
    <tr>
        <td>Number 1:</td>
        <td><input type="text" name="number1" value="<?php echo rand(1, 10); ?>" /></td>
    </tr>
    <tr>
        <td>Number 2:</td>
        <td><input type="text" name="number2" value="<?php echo rand(1, 10); ?>" /></td>
    </tr>
    <tr>
        <td>Tegevus:</td>
        <td>
            <input type="radio" id="korruta" name="tegevus" value="korruta" /> <label for="korruta">Korruta</label>
            <input type="radio" id="liida" name="tegevus" value="liida" /> <label for="liiga">Liida</label>
            <input type="radio" id="lahuta" name="tegevus" value="lahuta" /> <label for="lahuta">Lahuta</label>
        </td>
    </tr>
    <tr>
        <td>Vastus:</td>
        <td><input type="text" name="vastus" value="" /></td>
    </tr>
    <tr>
        <td colspan="2" style="text-align: right;"><input type="submit" name="arvuta" value="Arvuta" /></td>
    </tr>
</table>
</form>