The school board may provide for the setting aside and including as an operating expense of the project an amount of the estimated annual income and revenues, in the judgment of the board reasonably necessary, and use the same for the purchase and acquisition of athletic equipment, appliances, uniforms and clothing to be used by those engaging in the games, contests and exhibitions, and may supply the same on such terms or gratuitously to those participating in such games, contests and exhibitions as the board determines in view of the fact that the participants contribute their efforts and skills to the games, contests and exhibitions which produce the revenues.