code: public function getSuffixNotation($magnitude = null)
      {
          $magnitude = isset($magnitude) ? $magnitude : $this->getMagnitude();
          $exp = 3 * floor($magnitude/3);
  
          return new SuffixNotation(pow(10, -$exp) * $this->number, new MagnitudeSuffix($magnitude));
      }
docs: @param int $magnitude
  
  @return SuffixNotation