In many cases, we , php programmers need Roman number display I II III IV etc.

Here is a simple algorithm for that .

 1000, 'CM' => 900, 'D' => 500, 'CD' => 400,
     'C' => 100, 'XC' => 90, 'L' => 50, 'XL' => 40,
     'X' => 10, 'IX' => 9, 'V' => 5, 'IV' => 4, 'I' => 1);

      foreach ($lookup as $roman => $value)
     {
            // Determine the number of matches
             $matches = intval($n / $value);

             // Store that many characters
            $result .= str_repeat($roman, $matches);

            // Substract that from the number
            $n = $n % $value;
      }

      // The Roman numeral should be built, return it
      return $result;
}

?>