California Code, Business and Professions Code - BPC § 5524

Six of the members of the board constitute a quorum of the board for the transaction of business.  The concurrence of five members of the board present at a meeting duly held at which a quorum is present shall be necessary to constitute an act or decision of the board, except that when all 10 members of the board are present at a meeting duly held, the concurrence of six members shall be necessary to constitute an act or decision of the board.