Section 1606 - Mode of exercise of trustees' powers1. The powers committed by law to the trustees of a common school district must be exercised by them as a board. The board must meet for the transaction of business in accordance with notice of time and place.2. In a board composed of three trustees, when two only meet to deliberate upon any matter, and the third, if notified, does not attend, or the three meet and deliberate thereon, the conclusion of two upon the matter, and their order, act or proceeding in relation thereto, shall be as valid as though it were the conclusion, order, act or proceeding of the three; and a recital of the two in their minute of the conclusion, act or proceeding, or in their order, act or proceeding of the fact of such notice, or of such meeting and deliberation, shall be conclusive evidence thereof.3. A meeting of the board may be ordered by any member thereof, by giving not less than twenty-four hours' notice of the same.