The Montgomery County school board completed a month of controversial decisions on school closings early yesterday by voting to ensure the long-term survival of a school in one board member's neighborhood and then listening as the board's vice president said she was ashamed of the entire proceeding.

The clamorous six-hour meeting summed up, in substance and in symbol, a divisive year-long process that will set the course of education in the county for years to come.

In all, the board voted during the last month to close 28 schools by 1984, to alter boundaries and to change school busing patterns. The board's actions are expected to save the county more than $6 million over the next four years.

In its final session of voting, the board majority approved a much-debated boundary change that was not recommended by school superintendent Edward Andrews, but which will guarantee the future survival of Cresthaven Elementary, located in board member Marian L. Greenblatt's Silver Spring neighborhood. The change added significantly to the number of students who will attend the school, virtually assuring that it will not have to be closed in the future because of declining enrollment.

It was this action, along with others taken during the month of voting, that led board vice president Elizabeth Spencer to declare that the board had "utterly destroyed" the superintendent's plan by making unnecessary "piecemeal" changes.

"Unfortunately, the resolutions adopted leave us, as a body and as individuals, open to charges of payoffs or the dispensation of special favors," Spencer said in the evening's concluding remarks. "I am ashamed to be a party to these actions."

Spencer's comments came after residents of the Takoma Park community entered the Wheaton High School auditorium shortly after midnight, where the board was meeting, carrying signs and shouting that the board's decisions had been unfair.

Earlier in the evening, Spencer attacked a motion by Greenblatt that will expand Cresthaven's boundary by adding to it 68 students from a school to the north, Jackson Road. The board already had voted to send to Cresthaven 67 students who now attend Brookview Elementary that will close next year.

Andrews had said that, with the addition of Brookview students, Cresthaven did not need to expand further to be assured of survival. By drawing students out of Jackson Road, the future of that school could be jeopardized, according to parents from the area who fought the boundary change.

During hearings last month, some Jackson Road parents urged Greenblatt, who has a son in the third grade at Cresthaven, to disqualify herself from voting on the boundary change "to avoid even the appearance of a conflict of interest." At the time Greenblatt dismissed the suggestion as "a cheap shot."

Board member Joseph R. Barse, who supported the boundary change, explained that Cresthaven is not likely to be a candidate for closing and therefore should be strengthened as much as possible. Another reason for the boundary change, Barse said, was to "introduce new socioeconomic diversity" into Cresthaven, which now has a minority enrollment of roughly 30 percent and few children from apartment complexes in the New Hampshire Avenue area.

Members of the Cresthaven community had lobbied against the closing of Brookview last year, when it appeared that many of the school's low-income minority students would be sent to Cresthaven. Many of those Brookview students will be sent to schools below the Capital Beltway as a result of this month's board action.

Under Greenblatt's plan, Cresthaven's minority enrollment will increase to roughly 41 percent.

Although there was no mention during the meeting of conflict of interest, board member Eleanor D. Zappone, a Greenblatt ally who lives near Cresthaven, cautiously pointed out that her vote was "not a personal matter" because none of her children attends the school.

The debate over the Jackson Road and Cresthaven boundary was symbolic of a larger rivalry between the two New Hamphire Avenue communities. Board president Carol F. Wallace, who lives near Jackson Road, said after the vote was taken that board's move amounted to "the Cresthaven relief act of 1982."

In opposing the boundary change, Spencer warned that by deviating from the superintendent's plan the board was "lousing up everything for the county for years to come."

"Some of us seem destined to leave the spoils behind and go on to other offices," Spencer said in a pointed reference to Greenblatt, who is expected to run for higher office.

Barse said the board was not elected to be "a rubber stamp" for the superintendent and that Spencer's comments were "simplistic."

She retorted later, however, saying that alternate motions adopted by the board "are equally simplistic" and were based on "whatever element, of our criteria or otherwise, best suited the purposes of the alternate resolution."

"The decisions taken to date, I believe, are destined to create the most divisive situations Montgomery County has ever experienced," she said.