ยง 1606. Mode of exercise of trustees' powers.  1. 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.
Structure New York Laws
Title 2 - School District Organization
Article 33 - Common School Districts
1601 - Trustees Constitute a Board and Body Corporate.
1602 - Number of Trustees; Determination of Change.
1603 - Property Held by Trustees as Corporation.
1604 - Powers and Duties of Trustees.
1604-A - Temporary Investment of School Moneys.
1605 - Powers and Duties of a Sole Trustee.
1606 - Mode of Exercise of Trustees' Powers.
1607 - Powers of Trustees When Vacancies on Board Exist.
1608 - Estimated Expenses for Ensuing Year.
1609 - Annual Report of Trustees of Certain Joint Districts.
1610 - Trustees' Annual Report to District.
1611 - Penalty for Failure of Trustee to Account.
1612 - Payment by Trustee to Successor.
1613 - Trustees' Right of Action Against Predecessor.
1614 - Notice of Non-Payment of Moneys Apportioned.
1615 - Taxation for Expenses Incurred by Trustees.
1616 - Issuing Order in Excess of Available Funds a Misdemeanor.