CHICAGO (CBS) — The Chicago Public Schools system is dangling $100,000 prizes to schools that most creatively design their longer school days.

As WBBM Newsradio’s Bernie Tafoya reports, CPS plans to award as much as $3 million to 30 schools next year. CPS says it is still trying to come up with the grant money through private donations.

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

All schools will be on a longer 7 1/2 hour day starting next year. CPS says it is looking for schools to show innovative ways to best use that extra class time, to get students to learn more, and to get teachers to work more closely together.

“Both the quantity and quality of instruction can mean the difference between a high school dropout and a college graduate,” CPS chief executive officer Jean-Claude Brizard said in a news release. “What you do with instructional time in the classroom is critical to boosting student achievement.”

Award winners will be announced in March.

So far, 13 Chicago Public Schools have enacted the longer school day, following a controversial push by Brizard and Mayor Rahm Emanuel.

The Chicago Teachers Union was infuriated when Emanuel and Brizard urged schools to break ranks with the union and go ahead with the longer school day on their own. The schools that complied received an extra $150,000 in funding from CPS, and teachers at the schools received $1,250 bonuses and 2 percent raises.

The union then sought an injunction to block the longer day from taking effect this year. Teachers Union president Karen Lewis argued that Emanuel and Brizard violated the union’s contract by allowing some schools to break ranks.

But the union abandoned its push for a court injunction, after the city agreed not to lengthen the day at any additional schools this year.