A school board, by resolution and subject to the approval of the governing body, may establish accounts in each of its departments and schools committed solely for the purchase of instructional materials and office supplies. The school board may authorize the transfer of a percentage of the funds budgeted for a school or division department, not to exceed thirty-five percent of the allocation, into such account. Such account shall be managed by the principal of the school or head of the division department who shall file a monthly accounting of the funds with the division superintendent. No additional funds shall be transferred into any such account unless the monthly accounting has been filed. The funds in the account may be disbursed for payment of obligations by issuing a negotiable check signed by the principal or head of the division department, and a second person to be designated by the school board. At the close of the fiscal year, all funds remaining in the accounts shall be returned to the school board simultaneously with a full accounting of the disbursements. All such accounts shall be subject to the requirements of § 15.2-2511 and relevant provisions of the Virginia Public Procurement Act (§ 2.2-4300 et seq.).