The articles of incorporation of any corporation may provide that at all elections of directors of the corporation, each stockholder shall be entitled to as many votes as shall equal the number of votes which (except for such provision as to cumulative voting) he would be entitled to cast for the election of directors with respect to his shares of stock multiplied by the number of directors to be elected, and that he may cast all of such votes for a single director or may distribute them among the number to be voted for, or for any two or more of them as he may see fit, which right when exercised, shall be termed cumulative voting.