It grew from a giggle to a chorus of guffaws. The irony was just too much for Jackson Elementary School parents last week. Arlington school board members were saying nice things about their school.

"If it's such a beautiful school, why was it closed?" asked parent Tish Van Patten after the school board voted to move the George Mason Center for Special Education into Jackson at the end of this school year.

The Jackson contingent was not at the meeting to learn about the fate of students.

Because the school board voted three months ago to close Jackson to regular elementary classes at the end of the current school year, the 247 students now in kindergarten through fifth grades will be moved next September. And Jackson parents have let the school board know they will be satisfied with only one redistricting plan.

"We do not want to be dissected into many pieces," said Jackson parent Vincent Scoffone at an earlier meeting where he outlined the only option parents would approve -- splitting the Jackson enrollment between just two schools, McKinley and Glebe. Those schools, said Scoffone, appear to have the best chance of surviving any future school consolidations. And no Jackson students, he aruged, should be subjected to two school closings during their elementary school years.

"The Jackson children should not be used as experiments to cure an incurable disease . . . declining school enrollments," Scoffone argued.

But the school board also is hearing from supporters of other elementary schools who are asking for a share of the Jackson students to boost their own sagging enrollments. At a public hearing this week, parents from Ashlawn and Reed elementary schools, which survived the same three-month consolidation process that led to Jackson's closing, argued that a more equal distribution of Jackson students was the only fair solution.

"I am here to seek assurance that the board has not made any policy decision that would preclude giving Ashlawn long-term stability," said William Sweeney Jr., an Ashlawn parent.

"Are we parents correct in assuming the school board is considering all of the redistricting proposals?" asked Elleen Churchill, a Reed parent.

The speakers were referring to a report released last week by Superintendent Larry Cuban, which recommended merging the present Jackson attendence area with McKinley and Glebe. That report also recommended that neither Ashlawn nor Reed be considered for further consolidation until 1981. The second recommendation did little to soothe the Ashlawn and Reed supporters who have been fighting to save their schools for more than a year.

"It undoes the whole consolidation process, which was based on establishing some stability for the area," said Joan Horwitt, leader of the Ashlawn Coalition.

Earlier this month, Cuban recommended that the Jackson enrollment be divided among Ashlawn, McKinley and Reed. That recommendation provoked a howl of protest from the Jackson parents who expressed "bitterness," "frustration" and "unadulteralted anger."

The school board directed Cuban's staff to prepare alternatives to that recommendation showing the effect of redistricting students to just two schools. On the basis of that directive, Cuban said last week that he changed his recommendation to send the Jackson students to just two schools.

But school board members indicated last week they were not convinced Cuban's second recommendation was a fair one. Board member Mary Margaret Whipple said she feared that by not sending some Jackson students to Ashlawn and Reed, the decision would represent a "de facto school closing in advance" because of expected further declines in enrollment.

The school board will discuss redistricting plans at a work session tonight.

The fuel decision is expected next Thursday.