The teachers union said talks have not been amicable, but there seemed to be hope Tuesday as both sides sat at the negotiating table for a good part of the afternoon.
Class sizes and wages are key sticking points.
"They'll be teaching a class of 22 students. Then next period they'll be teaching a class with 40 student," said Tom Domenz, art teacher.
"Some of my classes are oversized, and as a foreign language teacher, it affects the amount of time each student gets to speak," said Beth Biallas, French teacher.
Students and parents had mixed opinions on the strike.
"What the teachers are asking for, is for us. So the least I can do is support them and do everything I can to stand there in solidarity with them today," said Desiree Sulzmann, student.
"I feel the teachers should not have walked out. Even though I agree on some of the points they want, they're letting down the children by walking out today," said Curtis Flint, parent.
On the eve of the strike, the northwest suburban school teachers were busy making signs for the picket lines, which they were expected to walk Tuesday. The union called for the walkout after the latest round of talks with the school board ended without any progress.
"It's the same thing we've been bargaining since day one of this contract. Without lower class sizes, education suffers. Without being able to attract and retain, the education in this district will suffer," said teachers union spokesman Mike Williamson.
The school board say it has made compromises with the union, but it says the union's demands could force the district into deficit.
"I can absolutely speak for the entire board saying none of us believe that it is the appropriate time in this terrible economy to go to our taxpayers and ask them for more money. That's just not gonna happen," said Joe Stevens of the Board of Education.
Some parents like Dean Conomikes said they hoped an agreement would be reached soon to get kids back in school. His son Patrick, a freshman at Jacobs High School, doesn't mind the break, as long as it's brief.
"I'm actually loving it. Get some time off, sleep in. The break is coming up. It's a good time to sit back and relax," Patrick Conomikes said.
"I'm disappointed. I was hoping they'll come to an agreement," Dean Conomikes said.
Meanwhile, some schools, including Carpentersville Middle School, are offering emergency childcare during the strike.