Striking teachers agreed to return to the classroom Monday in three school districts in Illinois, Massachusetts and Pennsylvania, but the academic year still remained on hold for more than 90,000 students in six states.

The end of walkouts in the suburban Philadelphia school district of Spring Ford, and in Lowell, Mass., and Blue Ridge, Ill., reduced the number of students out of school to fewer than 100,000 for the first time since the academic year began.

Last week, walkouts by 10,609 teachers affected 113,872 students in Michigan, Illinois, Ohio, New Jersey, Pennsylvania and Massachusetts. Nearly all the disputes involved salary issues.

Strikes extended summer vacation for 39,553 students and 2,554 teachers in 10 Pennsylvania school districts last week, and in Michigan, strikes in nine districts affected 42,064 students and 2,349 teachers.

No progress was reported during the weekend in Michigan.