Updated 07/24/12 – 6:06 p.m.

CHICAGO (CBS) — In an agreement both sides called a “win-win” scenario, the Chicago Public Schools have agreed to hire nearly 500 new teachers to achieve its goal of a longer school day, without significantly increasing work hours for teachers.

It’s a move removes one major roadblock towards a new contract between CPS and the Chicago Teachers Union, although salary, benefits and other issues are still unsolved.

CBS 2 Chief Correspondent Jay Levine reports, while teachers will undoubtedly seek more than the 2 percent raises offered by CPS, since they are no longer being asked to work longer hours than last school year, reaching an agreement on salary should be easier than if they were being asked to work up to 75 minutes longer each day.

In order to avoid having teachers working a school day that is 20 percent longer than now, the school district agreed to hire 477 new teachers to handle the extra programs included in the longer school day, according to Chicago Board of Education President David Vitale.

Chicago Teachers Union President Karen Lewis said that will allow for schools to teach “enrichment” subjects like art and music.

“It’s not just art and music, it’s P.E., world languages, computer tech, the things that make school better,” Lewis said.

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Mayor Rahm Emanuel also lauded the agreement, saying it would mean schools no longer have to sacrifice “enrichment” programs like art and music in order to maintain the basic time needed for the core subjects of reading, writing, and math.

“Principals and teachers in every school will no longer have to choose between math and music. Principals and teachers will no longer have to choose between arts and algebra. Principals and teachers will no longer have to choose between reading and recess,” the mayor said. “Our kids, from now on, receive a full education like every one of their parents did, and every one of their peers throughout this nation.”

Lewis said the city has also agreed to recall rights for tenured teachers who were fired in 2010, 2011 and 2012, and those teachers will have first rights at all new teaching openings. Principals would still have discretion over which teachers would best fill the positions, and teachers who are hired for the new jobs must have had a satisfactory or better grade on their last performance rating.

Vitale said the new hires would work primarily in elementary schools, which are seeing a much larger increase in the length of the school day.

Emanuel said the longer school day would mean an extra 1 hour and 15 minutes of classroom time for elementary school students, and an extra 34 minutes for high school students.

“We will add more time for classroom instruction than at any other time or any other year in the history of the Chicago Public School system,” the mayor said.

Lewis said the agreement would allow students to have more instructional time, without requiring existing teachers to work 20 percent longer without also getting a significant raise.

Regular classroom teachers will continue to work the same hours as before, while the new hires will teach the additional subjects that would be added to the school day.

School officials noted the 7-hour elementary school day and the 7.5-hour high school day are the same times they have been pushing for since April.

Lewis said the agreement was a win for all sides.

When reporters asked why it seemed like both sides were declaring victory over the agreement on the longer school day, Lewis said both sides did win — the district got the longer school day for students that it sought, while existing teachers will not be asked to work a significantly longer school day without a significant pay hike.

“We both won. That’s the whole point. I mean, that’s what a contract is, right? It should be win-win,” she said. “What, I mean, so we’re just going to fight each other forever? No, come on, let’s move on.”

Vitale said the agreement would allow the system’s “Track E” year-round schools to start the school year on Aug. 13, as scheduled.

The mayor praised both Chicago Public Schools officials and the teachers union for working together to reach an agreement on the longer school day, amid contentious contract talks.

“I hope they will continue this spirit of cooperation in resolving the remaining issues,” the mayor said. The district and the union have yet to reach an agreement on other core contract issues, such as teacher salaries, and both sides declined to discuss those elements of the ongoing contract talks on Tuesday.

It was still unclear how the district plans to pay for the new hires, while already trying to close an existing $665 million budget gap by raising the property tax levy to the legal limit, and draining its entire reserve fund.

Vitale estimated the cost of hiring the 477 new teachers would be $40 million to $50 million. Sources close to the mayor said, when contract negotiations are complete, there will be $50 million available to pay for the extra teachers.

While the breakthrough on the longer school day could make a teachers’ strike less likely, there are still several matters to resolve, including pay raises for teachers, health care benefits, and other issues.

“This is movement in the right direction, but let me make very clear this does not settle the outstanding and mandatory issues in the contract,” Lewis said.

Lewis declined to discuss the issue of teacher raises on Tuesday.

If no contract agreement is reached, the earliest teachers could strike is Aug. 18 after a 30-day cooling off period. Some teachers, though, go back to work on Aug. 6 with classes starting on Aug. 13.

Pressure to avert a strike is on both sides, CBS 2 Chief Correspondent Jay Levine reported last week. The mayor has yet to make good on campaign promises of stronger schools and safer streets. Teachers, with average salaries of $76,000 a year, risk a backlash from parents making far less — if they have jobs at all.

Last Wednesday, the Chicago School Board and the union both unanimously rejected a fact-finding report by arbitrator Edwin Benn with suggestions on how to end the contract stalemate. The report advised that teachers should get a pay raise of nearly 15 percent next year, and about 35 percent over four years.