A judge yesterday gave Cleveland school officials an extra day to prepare for a court-ordered negotiating marathon aimed at ending a school strike that has idled 101,000 students for three weeks.

Seattle teachers, saying that ignoring a court's back-to-work order would set a bad example for their students, agreed to return to work to day and begin the school year for 55,000 students.

In Cleveland, Cuyahoga County Common Pleas Court Judge Harry Hanna ordered around-the-clock negotiations to end the city's strike - largest of a number of walkouts that continue to curtail schooling of more than 250,000 students in a dozen states.

Hanna, who has denied school board requests for a back-to-work order, told school officials to reshuffle the budget and find money needed to grant raises to striking teachers and nonteaching personnel.

The school board slated a budget session last night and indicated the spending revisions would involve layoffs for hundreds of school employes.

In Tacoma, Wash., negotiations to end a strike by 1,800 teachers bogged down. The school board sought a back-to-work order and tentatively set Tuesday as the first day of school for the district's 31,000 students.

Other walkouts affected students in Indiana, Massachusetts, Maine, Michigan, Pennsylvania, Minnesota, New York, New Jersey, Connecticut and California.