The Montgomery County Council has approved 57 percent of County Executives Charles W. Gilchrist's cuts in the public schools' operating budget for next year, bringing the total down to $334.1 million, or $2.4 million less than the Board of Education requested.

In several work sessions last week, the council approved elimination of 105 of the 210 jobs Gilchrist wanted to cut, set aside $350,000 to pay for gasoline in case prices go beyond Superintendent Edward Andrews' modest estimates, and reduced the amount of money available to pay private-school tuition for handicapped youngsters.

Andrews defended the school budget, saying, "The fact that the county executive's (cuts) are in the classrooms means the rest of the budget is tight. While only 1 percent is denied by the county executive, it's a crucial 1 percent. The classroom is where it makes the difference."

Both Andrews and the school board had made their primary spending reductions in the area of administration. The council took a close look at the schools and teachers, and supported elimination of 20 senior-high teaching positions, 26 middle-school teachers and five junior-high teachers. The council said it believed current class sizes could be maintained even with fewer teachers, because of the closing this year of two junior highs and one middle school, and because high school classes have been growing smaller over the past three years.

The council rejected Gilchrist's elimination of 18 elementary-school teaching jobs because kindergarten and elementary enrollments increased last year. It also did not approve a reduction of 19 teacher-assistant jobs in elementary schools, another Gilchrist recommendation. School officials told the council they expected Title I federal funds (for educationally disadvantaged elementary pupils) would be reduced, and asked for county funds to make up the shortfall in teacher-assistant salaries.

The council also voted against the addition of six art, music and physical-education teachers, and approved two of five teaching positions for the "gifted and talented" programs. The council approved 7 of 19 requested safety and security positions, to be filed by guards who will screen persons entering school buildings and help patrol hallways and school grounds.

The county government's cuts represent "one of the lower reductions in recent memory," said Ken Hill, school budget director. "There is no question about it. This is the superintendant's second budget, and the message is loud and clear that he did a super job on both budgets before they got here."

The school board presented its proposed budget to the County Council and the executive on March 1. Gilchrist made a list of recommended cuts, called "denials," and the council later voted on each item -- cuts, called "denials," and the council later voted on each item -- either to accept the denial or keep the money in the budget. The budget will be adopted officially by the council on Friday.

In denying $111,800 for elementary textbooks, the council said it was convinced the school system had more textbooks than believed, because many of the elementary schools were not returning books to the warehouse as enrollment dropped.

The council also deleted $200,000 from funds to pay private-school tuition for handicapped children. The $200,000 will be set aside for use in case tuitions rise more than 33 percent from fiscal 1981 to fiscal 1982, which begins in July.

The school board had requested a budget of $336.5 million for fiscal 1982, a sum that included $22.9 million to cover a 9.5 percent cost-of-living raise for school employes. The board voted unanimously to back the full pay increases. Gilchrist originally recommended cutting the budget by $3.6 million, and on April 30 asked for additional cuts totaling $610,580, in the form of 27 fewer professional positions. Gilchrist said the board had overestimated state funds the county would receive.

A sensitive dispute with the school board arose over $9,000 that the board deleted from its budget by changing the position of assistant superintendent in charge of student affairs to a half-time job. Student leaders hobbied vociferously at every opportunity in the budget process to restore the position, held by Mike Michaelson.

School board members protested the council's move to add the money for the fulltime position to the budget, saying they wanted to lower the pay to a teacher-level salary, instead of its current principal-level salary. The board chose to make the job half-time instead of going through reclassification procedures.

The council voted 4-0 with 2 abstentions to make the $9,000 available to the board to keep the job fulltime. Council member Scott Fosler said he abstained from the voting "because we have to set some limits on what we get involved in." Member Rose Crenca, also abstaining, said, "It's an internal situation which is best handled by the superintendent and the school board."

Discussion of special education mirrored earlier sentiments expressed by some school board members, who questioned whether Montgomery County was spending more money than necessary on such programs.

Before Public Law 94-142 was enacted in 1975, requiring public schools to provide handicapped youngsters with a free and appropriate education "in the least restrictive environment," Montgomery County was light years ahead of other jurisdictions in serving handicapped youngsters and many were attracted to the county, according to Hiawatha Fountain, head of the continuum education division.

Fewer students came to Montgomery County for its special-education programs after the enactment of PL 94-142 brought a general improvement in such programs nationwide, Fountain said. But he predicted that the present trend toward federal deregulation may again bring families with handicapped youngsters to Montgomery schools.

Andrews asked the council to make up approximately $587,000 in federal funds he expects to lose in programs for the handicapped. The council said it would take up the matter later if the federal funds are withheld.