public function getDisplayRoundingFactor( $decimal )
	{
		// Simple chcck
		if ( ! is_numeric( $decimal ) || $decimal == 0 ) return 1;

		// Note: using '==' so the array value is coerced to zero
		if ( ! isset( $this->displayRoundings[ $decimal ] ) || $this->displayRoundings[ $decimal ] == 0 )
		{
			$this->setDisplayRoundingFactor( $decimal, abs( $decimal ) );
		}

		return $this->displayRoundings[ $decimal ];
	}